bluuebunny/crossref_metadata_2025 huggingface dataset:
Property Control for High-Quality Ba1-xKxBiO3 Epitaxial Thin Films Prepared by High-Pressure Reactive rf-Magnetron Sputtering
Authors: Iyori Masahiro , Suzuki Seiji , Suzuki Hiroshi , Yamano Koji , Takahashi Kazuhiko , Usuki Tatsuro , Yorinobu Yoshisato Yorinobu Yoshisato , Shoichi Nakano Shoichi Nakano
Published: February 2005

The electrical properties of Ba1-x
K
x
BiO3(BKBO) epitaxial thin films on SrTiO3(110) substrates have been successfully controlled using high-pressure reactive rf-magnetron sputtering under an 80-Pa discharge gas. We investigated the relationship between the target composition and the electrical properties of BKBO films. The zero resistance temperature (T
ce) and the temperature dependence of resistivity above the superconducting onset temperature (T
co) were found to be primarily influenced by the ratio of Ba/K and the Bi content of the target composition, respectively. Electrical measurements showed that the highest Tce of as-grown BKBO epitaxial film was 28 K.
Bonding Effects and Electronics States in Ba1-xSrxTiO3 System
Authors: Acharya Bhabani Sankar , Rajeev Rajeev , Laxmidhar Pradhan Laxmidhar Pradhan
Published: February 2005

X-ray emission spectra in stoichiometrically highpurity Ba1-x
Sr
x
TiO3 (x=0 to 1) powder have been investigated because of the poor understanding of the physics of electronic structure in such systems. The Sr Kβ emission band was found to contain two bands around 15.88 and 16.15 keV attributed to Kβ1 and Kβ3 respectively. The Ti Kβ emission spectra were found to shift towards low energy side with the increase in Sr concentration. The binding energy (BE) of L level remains unchanged with the Sr concentration. From these observations it has been possible to conclude that change in the stoichiometry of the compound does not change the process of multiple ionisation or core hole-electron interaction. Further for Ti Kβ emission, it has been possible to say that 4p states of Ti hybridises with 2p states of oxygen and this hybridisation decreases with the increase in vacancies in the system. This results in pushing up the Fermi level E
f.
V and Ti Doping Effect on In-Ag-Te-Sb Optical Phase Change Rewritable Disc
Authors: Tominaga Junji , Handa Tokuhiko , Susumu Haratani Susumu Haratani , Suguru Takayama Suguru Takayama
Published: February 2005

In-Ag-Te-Sb is known as one of the alloys suitable for optical phase change recording, which has a high erasability at the linear recording velocity of around 7 m/s. The phase change rewritable recording succeeded at the linear recording velocity of 1.4 m/s with 0.5 at.% doping of Ti or V atoms, which delayed the crystallization time drastically, but maintained the high erasability. It was possible to make 103 repetition recordings with jitter in the reproduced signal of less than 40 ns, when the eight-fourteen modulation (EFM) signal, which is generally used for compact discs (CD), was applied.
Molecular Orbital Calculations on Iron Disilicide β-FeSi2
Authors: Shin-ichiro Kondo Shin-ichiro Kondo , Masayuki Hasaka Masayuki Hasaka
Published: February 2005

Ab initio molecular orbital calculations were performed on two types of FeSi8 clusters forming crystalline β-FeSi2 to examine electronic states. Mulliken population analysis on both clusters shows that d-s hybridized orbitals are predominant at a low energy level and d-p hybridized orbitals gradually become predominant with increase in energy. Since d-p hybridized states close to the highest occupied MO (HOMO) level are found to be π-type antibonding for both clusters, d-p antibonding states between Fe and Si atoms are assumed to be formed near the Fermi level in actual crystalline β-FeSi2.
Angular Dependence of Transmission Properties in Polymer-Dispersed Liquid-Crystal Cells with Memory Effects
Authors: Sato Susumu , Yamaguchi Rumiko , Stefan Dickmann Stefan Dickmann , Dieter A. Mlynski Dieter A. Mlynski
Published: February 2005

Polymer-dispersed liquid-crystal (PDLC) cells are prepared using a UV-curable methacrylate prepolymer and nematic liquid crystals with a positive or a negative dielectric anisotropy. Memory effects, created by the phase transitions from an isotropic to a nematic phase with application of a magnetic field, of light transmission properties of the PDLC cells are described and their angular dependence is measured and discussed. A new type of optical filter which transmits the incident light only in directions oblique to the normal of the cell in an off-state is demonstrated using both positive-type and the negative-type PDLC cells. A broad transparent on-state and an opaque on-state can be attained by applying voltage across the positive-type and negative-type PDLC cells, respectively.
Growth of Oriented NiS Films on Si(111) and Al2O3(012) Substrate by Pulsed Laser Ablation
Authors: Lee Heayeon , Kanai Masaki , Tomoji Kawai Tomoji Kawai , Shichio Kawai Shichio Kawai
Published: February 2005

We report for the first time the deposition of NiS films
on etched Si(111) and (012) using pulsed laser
ablation. NiS films in the hexagonal(β)phase were
formed at a S:Ni target composition of 2:1 and at a
substrate temperature of 350°C. Films were obtained on
Si(111) and Al2O3(012) substrates. The films on Al2O3(012)
exhibited c-axis orientation over a wide range of
substrate temperatures.
Point Defects in Cubic Boron Nitride after Neutron Irradiation
Authors: Atobe Kozo , Honda Makoto , Ide Munetoshi , Yamaji Hiromichi , Matsukawa Tokuo , Fukuoka Noboru , Okada Moritami , Nakagawa Masuo
Published: February 2005

The production of point defects induced by reactor neutrons and the thermal behavior of defects in sintered cubic boron nitride are investigated using the optical absorption and electron spin resonance (ESR) methods. A strong structureless absorption over the visible region was observed after fast neutron irradiation to a dose of 5.3×1016 n/cm2 (E>0.1 MeV) at 25 K. This specimen also shows an ESR signal with g-value 2.006±0.001, which can be tentatively identified as an electron trapped in a nitrogen vacancy. On examination of the thermal decay of the signal, the activation energy for recovery of the defects was determined to be about 1.79 eV.
Formation of n+ a-Si:H Thin Layer by Ion-Doping Technique
Authors: Yoshida Akihisa , Masatoshi Kitagawa Masatoshi Kitagawa , Takashi Hirao Takashi Hirao
Published: February 2005

Profiles and quantities of impurities implanted by an ion-doping technique have been investigated by secondary ion mass spectrometry (SIMS) measurements and MonteCarlo simulations. The ion-doping technique in this paper is one of large-area ion implantation without mass separation using an rf ion source. In the ion-doping experiments, the ion source gas used was 5% phosphine in hydrogen, and the ion acceleration voltage was in the range of 6 kV-30 kV. The hydrogen ions were estimated to be mainly H2
+ and H3
+, and some ions were PH
x

+. The fraction of ions containing phosphorus was about 50% of the total ion dose. Formation of an n+ a-Si:H thin layer by the ion-doping technique at room temperature was also confirmed from electrical measurements of doped a-Si:H films. The values of conductivities obtained were 10-4∼10-3 S/cm. The n+ a-Si:H layers formed by the ion-doping technique are applicable to the fabrication of a-Si:H thin-film transistors (TFTs).
Reliable Au Wire Bonding to Al/Ti/Al Pad
Authors: Hiroshi Ueno Hiroshi Ueno
Published: February 2005

In this paper, we describe bond degradation and the bondability of an Au wire to a thin-Al/Ti/Al pad. It is found that the pad structure of Al(300 nm)/Ti(300 nm)/Al(1000 nm) is useful for the prevention of bond degradation upon heat treatment at 473 K for 3.6 Ms. Use of the pad necessitated an annealing temperature of at least 723 K, because of its lower initial bond resistance. With heat treatment after thermosonic ball bonding, the bond resistance is almost invariable and the bond shear strength does not decrease. The life of the bond between the Au wire and the pad is extended with thickening of the Ti layer.
General Method to Determine the Position-Charge Relationship for Position-Sensitive Detectors with Variously Shaped Resistive Anodes
Authors: Hasebe Nobuyuki , Kiso Kazuhiro , Kaneda Eiji , Doke Tadayoshi
Published: February 2005

A new approach using the Green function instead of the method of Fourier expansion is presented to determine the position-charge relationship for radiation detectors employing a charge division on the resistive anode bordered by an additional resistive line. The resistive anode with a polygonal shape is considered as a general case. Theoretical consideration shows that the position of radiation incidence in the position-sensitive detectors is represented in the integral form containing the Green function if the total charge generated in the detector is assumed to be collected over an infinite time. Anodes with the geometries of a triangle, square, circle or spherical triangle are described as practical shapes. It is shown that, when the shape of the anode is (spherical) triangular or square, the relationship between the position and charge is determined by a harmonic function obtained from a simple geometric consideration.
Evaluation and Imaging of Materials Using Picosecond Laser-Induced Ultrasonics
Authors: Akira Harata Akira Harata , Tsuguo Sawada Tsuguo Sawada
Published: February 2005

We have developed a novel microscopic method named laser-stimulated scattering microscopy for the nonde-structive evaluation of surface modification of materials. It is a kind of laser microscope based upon space- and time-resolved transient reflecting gratings.
Application of Underwater Shock Wave Focusing to the Development of Extracorporeal Shock Wave Lithotripsy
Authors: Kazuyoshi Takayama Kazuyoshi Takayama
Published: February 2005

This paper describes a summary of a research project for the development of extracorporeal shock wave lithotripsy (ESWL), which has been carried out, under close collaboration between the Shock Wave Research Center of Tohoku University and the School of Medicine, Tohoku University. The ESWL is a noninvasive clinical treatment of disintegrating human calculi and one of the most peaceful applications of shock waves. Underwater spherical shock waves were generated by explosion of microexplosives. Characteristics of the underwater shock waves and of ultrasound focusing were studied by means of holographic interferometric flow visualization and polyvinyliden-difluoride (PVDF) pressure transducers. These focused pressures, when applied to clinical treatments, could effectively and noninvasively disintegrate urinary tract stones or gallbladder stones. However, despite clincal success, tissue damage occurs during ESWL treatments, and the possible mechanism of tissue damage is briefly described.
Highly Accurate CO2 Gas Sensor Using a Modulation-Type Pyroelectric Infrared Detector
Authors: Takeuchi Kousuke , Tanaka Toshiharu , Ikeda Masami , Shibata Kenichi , Sakauchi Yasuaki , Yamada Yasuhiro , Shoichi Nakano Shoichi Nakano
Published: February 2005

We have developed a highly accurate CO2 gas sensor which utilizes a pyroelectric infrared (IR) detector containing a solid state chopper and an optical filter. We have improved the noise of the IR detector and the dependence of the sensitivity on the optical filter characteristics. The noise of the IR detector is suppressed by optimization of the gate resistance value and by development of a new structure for IR sensing to compensate for extraneous noise. The magnitude of the noise is improved about one-half compared with the magnitude in the conventional detector. The sensitivity to CO2 has been raised by investigating the optimum conditions of the optical filter. The accuracy of the CO2 gas sensor using the new IR detector is ±0.03% at a 5% CO2 gas concentration and ±0.12% at a 20% concentration.
VHF Ultrasonic Resonator for Soft Materials
Authors: Haruhiko Nakajima Haruhiko Nakajima , Kenji Arakawa Kenji Arakawa
Published: February 2005

An ultrasonic resonator for measuring sound velocity in soft materials over a wide frequency range is designed and constructed, with special attention paid to the thickness matching and parallelism between transmitting and receiving transducers. The resonator is composed of x-cut quartz disks and has shown a very sharp spectrum in the frequency range of 3 to 200 MHz with practical signal strength. As an exemplifying data, the sound velocity change in the process of gelation of a chemical gel is presented. The possibility of a composite cavity which is operational over three decades of the MHz range is discussed.
Analysis of Internal Friction Peaks in the Intermediate Temperature Range of NaCl
Authors: Tateno Hiroto , Iwashita Youichirou , Akira Fukai Akira Fukai
Published: February 2005

We measured internal friction, Young's modulus, ionic conductivity corresponding to the density of vacancies and the dielectric loss corresponding to the dipole density at the same time by an automated Marx's composite oscillator method, in order to investigate the internal friction peaks of NaCl single crystal around 90°C. We observed peaks for both internal friction and dielectric loss, and interpreted the peaks to reflect relaxation by dipole reorientation.
Asymmetric Ultrasonic Pulse Radiation Using Electromagnetic-Induction Transducer and PZT(Pb(Zr-Ti)O3) Transducer with Wave Synthesis Method
Authors: Nobuyuki Endoh Nobuyuki Endoh , Koji Yamamoto Koji Yamamoto
Published: February 2005

In medical applications, especially in urology, we use a fragmentation calculus technique with shock waves. This technique is very profitable because of no abdominal surgery for a human being. Large negative sound amplitude pulses, however, can cause problems such as internal hemorrhage or pain in the human body. The final goal of this study is to develop a means to project an intense positive unipolar pulse without negative sound pressure. We improved a composite transducer consisting of an electromagnetic-induction-type (EMI) transducer and PZT (Pb(Zr-Ti)O3) transducers. An EMI transducer consisting of a metal coil and vibration membrane can project intense sound pulses into water. In order to suppress its negative sound pressure, we project a compensation pulse with PZT transducers using an inverse filtering method. An asymmetric pulse whose P+ to P- amplitude ratio was very high was projected in water.
Receiving Characteristics of d31-zero Piezo-Rubber Hydrophone
Authors: Ogura Kohji , Ogawa Masakazu , Kanji Ohya Kanji Ohya , Hisao Banno Hisao Banno
Published: February 2005

The piezoelectric properties and the receiving characteristics of d
31-zero Piezo-Rubber hydrophones are investigated. Piezo-Rubber is a piezoelectric composite material consisting of PbTiO3 and chloroprene rubber. The d
31-zero Piezo-Rubber hydrophones consisting of PT/PZT have almost flat frequency receiving characteristics. However, the d
31≠0 Piezo-Rubber hydrophones consisting of PT/PZT show some variations in the receiving characteristics. The relationship between the variation and hardness of Piezo-Rubber is discussed.
1.5 GHz Low-Loss Surface Acoustic Wave Filter Using ZnO/Sapphire Substrate
Authors: Koike Jun , Kazunobu Shimoe Kazunobu Shimoe , Hideharu Ieki Hideharu Ieki
Published: February 2005

A 1.5 GHz range low insertion loss surface acoustic wave (SAW) filter has been developed using a ZnO/sapphire substrate and IIDT-type electrodes with two external reflectors. This filter had an insertion loss of 1.3 dB, stop-band attenuation of greater than 30 dB and matching impedance of 50 Ω pure resistivity without external matching networks. This filter has the smallest insertion loss of all transverse-type GHz-range SAW filters reported previously and it is suitable for use as a RF-stage filter for future 1.5 GHz range Japanese digital cellular systems.
Application of Ion-Beam-Sputtered Al Films to Ultrathin Surface Acoustic Wave Devices
Authors: Kamijo Atsushi , Mitsuzuka Tsutomu , Yamamoto Yasushi , Tomotsune Kaoru , Tamichi Shigeru
Published: February 2005

Ion-beam sputtering technique has been applied to Al film deposition for electrodes in high-frequency surface acoustic wave devices. Al films having low resistivity and a smooth surface have been obtained, even in the ultrathin thickness range. It was shown that the ion-beam sputtering technique provided excellent thickness uniformity and controllability. This method was also applied to the deposition of highly preferred [111]-textured Al films.
Surface Acoustic Wave Properties on Proton-Exchanged 128°-Rotated Y-Cut LiNbO3
Authors: Kakio Shoji , Junji Matsuoka Junji Matsuoka , Yasuhiko Nakagawa Yasuhiko Nakagawa
Published: February 2005

The characteristics of surface acoustic waves on proton-exchanged 128°-rotated Y-cut LiNbO3 were investigated at a frequency of 100 MHz. The changes of the phase velocity and the electromechanical coupling coefficient as a function of the proton-exchange depth were measured. From these experiments, the elastic constants and the piezoelectric constants of the proton-exchanged layer were determined. The effects of annealing on the phase velocity and the surface acoustic wave propagation loss were also measured.
Accuracy of Surface Acoustic Wave Velocity Measured to Determine the Elastic Constants on LiTaO3 Substrate
Authors: Kouichi Yamamoto Kouichi Yamamoto , Yasutaka Shimizu Yasutaka Shimizu
Published: February 2005

Elastic constants can be determined from the experimental values of surface acoustic wave (SAW) velocities. In this paper, the measurement accuracy of SAW velocities is numerically obtained to determine elastic constants and their temperature coefficients. The velocities must be measured with an accuracy of more than 0.001 m/s and the temperature characteristics of more than 0.0001 ppm/°C.
Coriolis Force Mass-Flow Meter Composed of a Straight Pipe and an Additional Resonance-Vibrator
Authors: Hirohide Tsutsui Hirohide Tsutsui , Yoshiro Tomikawa Yoshiro Tomikawa
Published: February 2005

This paper deals with a new construction for a mass-flow meter using Coriolis force, and its basic experimental results. Some Coriolis force mass-flow meters, proposed up to now, are of a twin construction of, for example, a U-type pipe or a straight-type pipe, where the mass-flow is determined by measuring the relative displacement between the pipes. Therefore, their structure is too complex. To improve this situation, the authors propose a new mass-flow meter using one straight pipe, together with an additional flexural resonance-vibrator. The experimental results prove that a mass-flow meter can be realized by such a simple construction as dealt with here.
Humidity Sensitivity of Lamb Waves on Composite Polyimide/ZnO/Si3N4 Structure
Authors: Sato Manabu , Yamamoto Tatsuo , Takeuchi Masao , Yamanouchi Kazuhiko
Published: February 2005

The propagation characteristics and sensitivity to humidity of Lamb waves in a composite polyimide/ZnO/silicon nitride structure have been theoretically and experimentally studied. Measured values of phase velocity and the electromechanical coupling constant almost correspond to theoretical values. If we assume that the humidity dependence of polyimide stiffness almost coincides with that of polymethyl methacrylate, it is conceivable that in the low-humidity range, the change in phase velocity would be mainly due to change in polyimide density, and in the intermediate humidity range, due to change in polymide stiffness. When we normalize the sensitivity of phase velocity to humidity with the phase velocity and polyimide thickness, the sensitivity of Lamb waves is about six times that of Rayleigh waves.
Photolithography System Using Modified Illumination
Authors: Kamon Kazuya , Miyamoto Teruo , Myoi Yasuhito , Tanaka Hitoshi Nagata
Published: February 2005

Since the LSI pattern size has approached the exposure wavelength, various methods have been developed to overcome limitations in photolithography. This fact indicates that a shorter wavelength or some novel techniques will be needed in order to cope with finer patterns. The modified illumination method was proposed in order to improve the depth of focus and resolution limit. We applied the modified illumination method to the step-and-repeat exposure system. Experiments using modified illumination were carried out and sub-half-micron patterns were produced. The process latitudes of the modified illumination method are evaluated.
Shear Horizontal Acoustic Plate Mode Viscosity Sensor
Authors: Sato Toshio , Okajima Hiroshi , Kashiwase Yutaka , Nakajima Ryohei Motegi
Published: February 2005

Mode analysis of a LiTaO3 (LTO) plate has been carried out numerically, and an interference-free shear horizontal acoustic plate mode (SH-APM) suitable for measuring the liquid viscosity was found. A viscosity sensor having a liquid container on the side opposite to interdigital transducers (IDTs) was fabricated on X-cut 148° Y-prop LTO. Satisfactory agreement was obtained between the calculated frequency spectrum and the experimental one. A loading test was carried out for a series of Newtonian liquids, which showed good agreement with the perturbation theory.
Dielectric Loss in a Piezoelectric Ceramic Transducer under High-Power Operation; Increase of Dielectric Loss and Its Influence on Transducer Efficiency
Authors: Hirose Seiji , Manabu Aoyagi Manabu Aoyagi , Yoshiro Tomikawa Yoshiro Tomikawa
Published: February 2005

Dielectric loss in a piezoelectric ceramic transducer is related to the vibration, and increases markedly under high-power operation. When PZT ceramics is used over the vibration velocity of about 0.25 (m/s), the dielectric loss becomes larger than the mechanical vibration loss. In this paper, the values of the resistances indicating the dielectric loss and mechanical vibration loss in the equivalent circuit are shown. If an equivalent electric circuit including these resistances is utilized, efficiency of the transducers operating at a high-power level may be calculated with more accuracy. By calculation of the efficiency, the maximum efficiency was obtained at the anti-resonance frequency, not at the resonance frequency. These facts cannot be explained by the ordinary equivalent circuit which does not involve dielectric loss related to the vibration.
A Finite-Element Analysis of Transient Vibration of an Ultrasonic Welding Tool
Authors: Yoshikazu Koike Yoshikazu Koike , Sadayuki Ueha Sadayuki Ueha
Published: February 2005

Transient vibration of an ultrasonic welding tool is computed in order to estimate the fracture of the tool. Equations for this analysis have been formulated by means of the finite-element method (FEM) and Newmark-β method. With the use of these equations, the transient stress distribution of the ultrasonic welding tool driven by a bolt-clamped Langevin-type transducer is calculated. Then, the effect of the transient state of the tool is investigated.
Ultrasonic Detection from Picosecond Surface Vibrations: Application to Interfacial Layer Detection
Authors: Oliver B. Wright Oliver B. Wright , Katsuhiro Kawashima Katsuhiro Kawashima
Published: February 2005

A new optical technique is used to detect picosecond ultrasonic pulses in thin opaque films by direct time-resolved detection of ultrafast vibrations of the film surface. For thin films of tungsten we show how the strain pulse shape in the film can be measured without significant distortion at frequencies around 100 GHz. The potential for characterization of thin film bonding and adhesion is demonstrated by the detection of an ultrathin interfacial amorphous silicon layer, of nanometre order in thickness, which is sandwiched between two different materials.
Relationship between Lamb Waves on Fluid-Loaded Plate and Underwater Acoustic Radiation in Region below than Coincidence Frequency
Authors: Uchida Hiroshi , Toshiaki Kikuchi Toshiaki Kikuchi , Akio Hasegawa Akio Hasegawa
Published: February 2005

The far field directional response radiated from a fluid-loaded plate vibrating with the zero-order Lamb modes is described in a region below than the coincidence frequency. The vibrated plate used is a brass plate. The transmitter used to vibrate the plate and the hydrophone used to receive the radiating wave are made of piezoelectric rubber. The directional responses of the radiating sound are obtained over a frequency range between 55 kHz and 330 kHz for a brass plate with a 1.5 mm thickness.
Resistivity Correction Factor for the Four-Ring Probe Method
Authors: Yamashita Masato , Nishii Toshifumi , Iwata Atsushi , Kurihara Hiroshi , Tanaka Nobuo
Published: February 2005

The four-ring probe method which was devised as a method of measuring resistivity is described. This method is applicable to the system consisting of a circular disk sample and a four-ring probe array. The resistivity correction factor (RCF), which is necessary for correcting data measured by means of the four-ring probe method and for obtaining the resistivity of the sample, is derived analytically. The properties of the RCF are discussed on the basis of the theoretical analysis. It is demonstrated by the experimental results that (i) the RCF corrects data accurately, (ii) it is insensitive to the shape of the sample and the measurement position as long as the thickness of the sample is less than the probe spacing, and (iii) the four-ring probe method is compatible with the four-point probe method.
Contour Detection of Underground Cylindrical Cavities by Means of Acoustic Pulse Reflection Method
Authors: Yamada Mitsuru Yoshida
Published: February 2005

A method for shallow underground cavity exploration based on the acoustic pulse reflection method using a sound source with a finite width in space is studied. The medium is assumed to be a half-space with a cylindrical cavity buried shallow underground, and an acoustic pulse with a normal stress is applied to the free surface. The scattered waves generated at the cavity boundary, observable at the receiver located at the surface, are calculated by the finite difference method. Using the scattered waves, the outer boundaries of the cavity contour are detected highly accurately by regarding the sound source as an array of the point sources.
Pressure Balancing Structure for Fiber-Optic Flexural Disk Acoustic Sensor
Authors: Sato Ryotaku , Ishii Hirokazu , Dobashi Koji , Saito Hiroshi Kamata
Published: February 2005

A design for a high sensitivity sensor utilizing the flexural vibration of circular disks, as the sensing element of an interferometric fiber-optic hydrophone to detect underwater sounds has previously been reported. To improve the durability of this type of sensor against static pressure, a sensor with a pressure-balancing structure was fabricated and tested. The measured receiving sensitivity of the sensor in the sea agreed reasonably well with the calculated sensitivity. The sensitivity measured in an acoustic coupler was independent of the static pressure up to 5 MPa.
Optical Detection of Acoustic Pressure Using Birefringence of (Pb, La)(Zr, Ti)O3 Ceramics
Authors: Koiwa Hideyo , Takahashi Sumio , Nagata Toshiaki Kikuchi
Published: February 2005

Birefringence of PLZT (9/65/35) is measured as a function of applied DC voltage. Hysteresis has been observed for the sample used. An experiment is conducted on the optical detection of acoustic pressure in liquid utilizing birefringence of PLZT (9/65/35). Linear dependence of the output signal on acoustic pressure has been observed for acoustic pressures from 146 to 181 dB re 1 µPa, and maximum sensitivity has been obtained at the optimum value of birefringence as predicted by calculations.
Effect of Ultrasonic Intensity on Sprouting
Authors: Chida Masaki , Ohdaira Etsuzou , Nobuyoshi Masuzawa Nobuyoshi Masuzawa , Masao Ide Masao Ide
Published: February 2005

Studies on effects of ultrasound on the growth of plants have been performed. However, conditions of exposure to ultrasound were not clear in these studies. This paper reports on the effects of ultrasound on sprouting. Experiments were conducted in a water tank, in which the ultrasonic fields were precisely measured. It was found that the growth of roots was most accelerated at an intensity level almost the same as the cavitation threshold. The amount of water absorbed by the seeds was increased upon ultrasonic exposure. Further, this paper clarified the relationship between acoustic pressure and state of the water absorbed by the seeds.
Quantitation of Fine Displacement in Echography
Authors: Masuda Kohji , Ishihara Ken , Yoshii Ken , Furukawa Toshiyuki , Kumagai Sadatoshi , Hajime Maeda Hajime Maeda , Shinzo Kodama Shinzo Kodama
Published: February 2005

A High-speed Digital Subtraction Echography was developed to visualize the fine displacement of human internal organs. This method indicates differences in position through time series images of high-frame-rate echography. Fine displacement less than ultrasonic wavelength can be observed. This method, however, lacks the ability to quantitatively measure displacement length. The subtraction between two successive images was affected by displacement direction in spite of the displacement length being the same. To solve this problem, convolution of an echogram with Gaussian distribution was used. To express displacement length as brightness quantitatively, normalization using a brightness gradient was applied. The quantitation algorithm was applied to successive B-mode images. Compared to the simply subtracted images, quantitated images express more precisely the motion of organs. Expansion of the carotid artery and fine motion of ventricular walls can be visualized more easily. Displacement length can be quantitated with wavelength. Under more static conditions, this system quantitates displacement length that is much less than wavelength.
Tracer for Ultrasonic Flow Visualization of Water/Solid Microparticle Suspension
Authors: Seki Masahiro , Tagawa Norio , Moriya Tadashi
Published: February 2005

A resonant-type ultrasonic tracer is developed and the relationship between the resonance frequency and the diameter of hollow magnetic microspheres is clarified experimentally. Flow visualization of a water/solid microparticle suspension characterized by Rayleigh scattering is demonstrated using the tracer.
Imaging Properties of the Diffraction Tomography by Compound-Scanning Transmitter-Receiver Pair Transducers
Authors: Yokoyama Tomoki , Keinosuke Nagai Keinosuke Nagai , Koichi Mizutani Koichi Mizutani
Published: February 2005

Imaging properties of the system which we proposed in the last symposium are studied. The transmitter-receiver system and the image-reconstruction algorithm have been improved. We can obtain images good enough for theoretically discussing the quality. We derive an equation of the resolution in the system which seems reasonable for the image obtained experimentally. We verify the effect of the para-axial approximation on the image to explain the darkness near the periphery of the scanned region.
Nondestructive Internal Observation and Distribution of Potential with Bias Application of npn Si Darlington Transistor Chip Using Electron-Acoustic Microscopy
Authors: Tabuchi Hiroshi Takenoshita
Published: February 2005

Study of an npn Si Darlington transistor chip under bias application was carried out using electron-acoustic microscopy (EAM). The results were as follows. (1) The distribution of potential in the chip with applied bias voltage could be determined. (2) The acceleration voltage (HV) of the irradiating electron beam was the major factor which determined the observable depth (t

x
) by EAM. (3) t

x
corresponded to approximately 60% of the range of excited electrons as a function of HV. Thus, EAM could nondestructively provide information on the internal structure of the device in the operating condition of the chip. The above results could not be obtained from the scanning electron microscopy (SEM) mode images.
Characteristic Evaluation of Lenses for Ultrasonic Micro-Spectrometer
Authors: Yanaka Masa-aki , Nakaso Noritaka , Katsumi Ohira Katsumi Ohira , Yusuke Tsukahara Yusuke Tsukahara
Published: February 2005

An ultrasonic micro-spectrometer (UMSM) was previously developed to measure the reflection coefficient of a solid specimen at a small spot on its surface. Lenses for the UMSM consist of a paired spherical transmitter and planar receiver, denoted as SPP lenses. In this paper, we show by both experiment and calculation that an acoustic field at the back focal plane of the spherical lens directly influences the incident angular dependence of the SPP lenses output. The acoustic field distribution depends strongly on the axial symmetry of the transducer in the spherical transmitter. Therefore, rapid variation of the field in the case of a circular transducer is successfully prevented by changing the transducer to a rectangular one, which is suitable for system normalization.
Study on Differential Photothermal Deflection Spectroscopy (PDS) Considering the Intensity Profile of a Probe Beam
Authors: Hata Tomonobu , Kazuriro Takahashi Kazuriro Takahashi , Susumu Horita Susumu Horita
Published: February 2005

This paper concerns an experimental and theoretical analysis of differential photothermal deflection spectroscopy (PDS) which we developed. In order to increase the sensitivity, intensity distribution of the probe beam was taken into account. When modulation frequency was constant, the experimental results were explained exactly by this theory. However, the frequency characteristics were not explained because of the diffraction of probe beams.
Effect of Thermal Donor Formation on the Photoacoustic Spectra of p-Si Single Crystals
Authors: Higashi Kouji , Ikari Tetsuo , Hirosumi Yokoyama Hirosumi Yokoyama , Koji Futagami Koji Futagami
Published: February 2005

Photoacoustic (PA) measurements of p-Si single crystals annealed at 450°C were carried out at room temperature near an optical absorption edge. The height of the pronounced peak at 1.07 eV, which appears only in the p-type samples, becomes smaller and disappear with an increase in the annealing time. Since annealing facilitates the thermal donor formation, the decrease in the peak height is explained by the compensation mechanism of the boron acceptors. The reappearance of the 1.07 eV peak with further annealing at 800°C for 30 minutes, where thermal donors are swept away, firmly supports our explanation.
Damage Depth Profiles in Ion-Implanted Silicon by the Photoacoustic Displacement Technique
Authors: Hara Tohru , Muraki Takeshi , Masataka Sakurai Masataka Sakurai , Satoru Takeda Satoru Takeda
Published: February 2005

Damage density measurement for ion-implanted silicon is studied, where the density is measured using Rutherford backscattering spectrometry (RBS) and a newly developed photoacoustic displacement (PAD) technique. Since correlation is obtained between the observed PAD and quantitative damage density in ion-implanted silicon at 150 keV at a dose of 2.0×1015 ions/cm2, damage density can be determined quantitatively from the PAD measurement at the surface. A damage density depth profile can also be obtained using the differential PAD measurement. The observed profile agrees well with the ones of the displaced atom density obtained by RBS measurement and Monte Carlo simulation.
Direct Observation of Growth Striations in a Liquid Encapusulated Czochralski GaP Crystal by Light Scattering Method
Authors: Tajima Michio , Takashi Iizuka Takashi Iizuka , Yasumasa Okada Yasumasa Okada
Published: February 2005

Growth striations in a liquid encapusulated Czochralski (LEC) GaP crystal doped with Te at the concentration of 6×1017 cm-3 was examined by the 90°-angle light scattering method. The growth striations were manifested as a periodical fluctuation in the scattering intensity along the growth direction in the core region of the crystal. The striations were found to be clearly correlated with chemical etching pattern, periodical Te fluctuation detected by electron-probe X-ray microanalysis and periodical cathodoluminescence signal by Te donor. The origin of the striated scattering pattern is attributed to the periodical distribution of the scattering centers formed by the preferential precipitation of excess Te on grown-in dislocations.
Chemical Vapor Deposition of Amorphous Silicon Using Tetrasilane
Authors: Kanoh Hiroshi , Osamu Sugiura Osamu Sugiura , Masakiyo Matsumura Masakiyo Matsumura
Published: February 2005

Hydrogenated amorphous-silicon films have been deposited by the plasma-free chemical-vapor-deposition method using tetrasilane (Si4H10) at temperatures as low as 350°C. The film deposited at 350°C and 9 Torr had hydrogen content as high as 15 at.%, optical bandgap of 1.78 eV, logarithmic ratio of photoconductivity (at a light intensity of 100 mW/cm2 under AM1 conditions) to dark conductivity of 3.2, activation energy of 0.78 eV and the Urbach tail slope as small as 56 meV. Thin-film transistors have been fabricated using the film deposited at 350°C. The electron mobility was 0.6 cm2/V s under as-deposited conditions.
Fabrication of DC Superconducting Quantum Interference Devices with Hybrid Structure of Polycrystalline Y1Ba2Cu3Ox Films and Epitaxial Y1Ba2Cu3Ox Films
Authors: Enami Hiroyoshi , Shinohara Toshiyuki , Kawahara Nobuaki , Suzuki Masanobu , Imura Hiroki Hoshizaki
Published: February 2005

Amorphous Y-Ba-Cu-O films were crystallized with patterned epitaxial Y1Ba2Cu3O
x
films by annealing. Grains of polycrystalline Y1Ba2Cu3O
x
were grown in the bridge-shaped amorphous area between the edges of epitaxial
Y1Ba2Cu3O
x
films. Dc superconducting quantum interference devices with granular-type Josephson junctions were fabricated using this method. In each Josephson junction, the site of grain boundaries in polycrystalline films was controlled in the middle of the Josephson junction bridge. Periodic magnetic field response with an output voltage modulation of 10 µV was observed.
Tracking Dependence on Readout Signal Characteristics of Two-Beam Optical Heads for Real-Time Verification
Authors: Shinoda Masahisa , Satoh Yasuyuku , Morihiro Karaki Morihiro Karaki , Kenjiro Kime Kenjiro Kime
Published: February 2005

The readout characteristics concerning the tracking offset of both the write spot and the read-only spot of a two-beam optical head for real-time verification have been investigated theoretically and experimentally. A formula for the optical disk model including both guide grooves and pits recorded by the write spot with a tracking offset has been derived and a two-beam optical head using a monolithic two-beam laser diode has been developed. The read-only spot, scanning at one half of the tracking offset of the write spot, has yielded the best results of real-time verification in both the results of theoretical analysis and experiment.
Lateral Growth of Extended-Chain Single Crystals of Vinylidene Fluoride and Trifluoroethylene Copolymers
Authors: Hikosaka Masamichi , Sakurai Katsuyuki , Koizumi Hiroji Ohigashi
Published: February 2005

Lateral growth of extended chain single crystals (ECSCs) of vinylidene fluoride and trifluoroethylene copolymers, P(VDF/TrFE), within the mobile hexagonal phase at high temperature and at atmospheric and high pressures was investigated directly by polarized optical microscopy. The VDF molar contents (x) studied were 0.75 and 0.78, which were less than x at the triple point (x=0.82) at atmospheric pressure. The lateral growth was steady growth. The plot of logarithmic lateral growth rate (log V) against the inverse of the degree of supercooling (ΔT
-1) gave a straight line, i.e., V=V
0 exp (-C/ΔT), where V
0 and C are constants, and does not show any breaking. These results confirmed that the lateral growth is mainly controlled by a two-dimensional nucleation process and shows only one “regime”. The number of ECSCs increased linearly with time, which indicates homogeneous nucleation.
Photoemission Study of Ag on Hydrogenated Amorphous Silicon
Authors: Tun-Wen Pi Tun-Wen Pi
Published: February 2005

We report a photoemission study of Ag overlayers deposited on a hydrogenated amorphous silicon (a-Si:H) film at room temperature, using synchrotron radiation as a probe. Unlike the two other interfaces, Au/a-Si:H and Cr/a-Si:H, where the metal deposits start to intermix with the a-Si substrate after a critical thickness is exceeded, the Ag/a-Si:H interface is abrupt without any indication of intermixing. The non-intermixing nature is reminiscent of its crystalline counterpart. More interestingly, we have found a unique behavior of small metal adatoms on a-Si:H; that is, they reside favorably on the dangling-bond sites. Strong hydrogen passivation on the surface prevents the gathered adatoms from coalescing.
Displacement-Current Generation from Spread Monolayers of Poly(vinyl alcohol)s Bearing Azobenzene Sides
Authors: Naruse Haruhiko , Ohnishi Koji , Iwamoto Mitsumasa , Ichimura Kunihiro , Seki Takahiro , Tamaki Takashi , Iriyama Keiji
Published: February 2005

Generation of displacement current across single monolayers of poly(vinyl alcohol)s bearing azobenzene sides was investigated with alternating irradiation with ultraviolet light and visible light. The displacement-current generation was accompanied by a change in the area occupied per molecule. The direction of the displacement-current generation was found to be explained by the change in the vertical component of dipole moment of monolayers perpendicular to the water surface due to the cis-trans photoisomerization.
Improvement of Bonded Silicon-on-Insulator using TCE-Grown Oxide as Buried SiO2
Authors: Huang Qing-An , Chen Jun-Ning , Hui-Zhen Zhang Hui-Zhen Zhang , Qin-Yi Tong Qin-Yi Tong
Published: February 2005

Silicon-on-insulator (SOI) was fabricated by wafer bonding using thermal SiO2 and trichloroethylene (TCE)-grown SiO2 as the buried oxides. Both the fixed charge density and the interface trap density at the back of silicon films on oxides were found to be appreciably lower for TCE-grown SiO2 than for dry-grown SiO2. The addition of TCE resulted also in significant increases of carrier lifetimes. The bonded SOI strength using TCE-grown SiO2 is comparable to that using dry-grown SiO2.
Extended Theory of Beam Loading in Electron Linac
Authors: Uetomi Isamu , Yamazaki Masaharu , Kobayashi Hitoshi , Sato Isamu
Published: February 2005

A new class of disk-loaded traveling-wave structures is proposed. This class is derived from direct generalization of conventional structures, and contains the constant-impedance (CZ) and constant-gradient (CG) structures as members. A beam-loading theory extended for this class implies that within the class, there exists a structure better than the conventional structures in field uniformity and other aspects, when a large-current beam is accelerated. A structure, taken as an example for the case of 10-MeV acceleration of a 1-A beam, is 12% shorter in dimension and 7% more efficient in microwave-to-beam power conversion than the constant-gradient structure.
Quantitative Analysis of Trace Hydrogen in Highly Purified Nitrogen Gas Using Rapid Reactions in Atmospheric Pressure Ionization Mass Spectrometer
Authors: Mitsui Yasuhiro , Irie Takashi , Saiki Hidekazu Okuhira
Published: February 2005

Quantitative analysis of trace hydrogen in highly purified nitrogen gas for the semiconductor fabrication process was investigated using an atmospheric pressure ionization mass spectrometer (APIMS). A previous method wherein the sample gas is directly introduced into the APIMS is not capable of providing high-sensitivity measurements for hydrogen in nitrogen gas. By mixing 20% argon gas with the sample gas, the sensitivity was increased to ten times that of the previous method. This is due to the occurrence of a previously unreported rapid reaction through which the quantity of hydrogen ions is increased: (N2Ar)++H2→N2H++H+Ar. The detection limit in this method and the rate constant for this reaction were estimated to be 40 ppt and 1.4×10-10 molecule-1 cm3 s-1, respectively.
Instrument for Measuring Viscosity and Shear Modulus under Steady Shear Stress
Authors: Tozaki Ken-ichi , Itou Tatsuya Miyatani
Published: February 2005

An instrument which can measure both shear modulus and viscosity under very low steady shear stress is described. Applicable shear stress for a torsion wire used was 1.02×10-4 to 3.4×10-3 N/m2. The measurable ranges of the shear rate and viscosity are from 7×10-1 to 6×10-7 s-1 and 1.4×10-4 to 6.0×103 Pa·s, respectively. By exchanging the torsion wire, maximum shear stress can be increased to 1.6×106 N/m2 and the measurable viscosity range is extended to 16 decades. Applicability of the instrument was tested for the thermo-reversible sol-gel transition of agarose solution, and the usefulness was confirmed. The minimum shear modulus measured here was 1.46×10-5 N/m2.
Fabrication of a Beryllium Window Sealed with an Au Gasket for Analysis of Characteristic X-Rays from Surface
Authors: Toshihiro Ichikawa Toshihiro Ichikawa
Published: February 2005

A window through which X-rays exit from a vacuum chamber into the atmosphere was fabricated from thin Be foil, using a ring of thin Au wire as a gasket for sealing.
Solvent-Substitution Effects on Weight and Volume Changes during the Desiccation Process of Egg-White Gel
Authors: Kanaya Haruichi , Hara Kazuhiro , Takushi Eisei , Kazumi Matsushige Kazumi Matsushige
Published: February 2005

The substitution effects for ethanol and acetone were investigated by means of simultaneous measurements of weight and volume during the desiccating process of egg-white gel. The time variations of the weight and volume in ethanol- and acetone-substituted gels were much different from those in the gel without substitution; the former showed gradual decrease, while the latter showed linear time dependence approximated by two lines in the semi-log plots. The structures in the desiccated specimens substituted with ethanol or acetone were revealed, through the scanning electron microscope (SEM) and X-ray photographs to differ greatly from those prepared from the nonsubstituted gel. Moreover, in the dehydration measurements carried out after soaking the desiccated specimens in water, all of the specimens showed almost the same features as the gel without substitution.
First Principles Study of the Effect of Tip Shape on Scanning Tunneling Microscopy Images
Authors: Watanabe Satoshi , Aono Masakazu , Tsukada Masaru
Published: February 2005

Effects of the shape of probe tip on observed scanning tunneling microscopy images have been investigated by first-principles calculations by taking the Si(111)√3×√3-Ag surface as an example of sample. By using three tungsten clusters with different shapes and by tilting their symmetry axes, various shapes of the tip were represented. Even for those tips which produce images distinctly different from experimental ones when their symmetry axes are normal to the surface, the images change so as to agree with experiments as the axes are tilted gradually. The results indicate that only one atom at the tip apex usually makes an essential contribution to the tunneling current and can explain why an experimental tip prepared quite arbitrarily usually produces good images.
Imaging of Organic Molecules by Atomic Force Microscopy
Authors: Hirofumi Yamada Hirofumi Yamada , Kan Nakayama Kan Nakayama
Published: February 2005

We have investigated the cleaved surfaces of polydiacetylene crystals, poly-PTS (2,4-hexadiyne-1,6-diol p-toluene-sulfonate) and poly-DFMP (poly-bis[2,2',5,5'-tetraaxistrifluoromethyl-phenyl]butadiene), and liquid-crystal molecules, 8CB (4'-n-octyl-n-cyanobiphenyl), on graphite by atomic force microscopy. Molecular resolved images of each sample were successfully obtained. The contrast mechanism of 8CB for the atomic force microscope (AFM) is discussed.