bluuebunny/crossref_metadata_2025 huggingface dataset:
Precise Determination of Residual Stresses in Large Specimens by Neutron Diffraction
Authors: Pirling Thilo , Hughes Darren J. , Robinson Jeremy S.
Published: June 2010

Experimental errors in neutron residual strain imaging are often underestimated, mis-understood or simply ignored. The choice of beam defining optics can play a large role in the magnitude of these errors. In this paper we show that the use of a traditional slit beam defining system with large specimens can lead to several sources of errors. Large specimens usually require necessarily large distances between the slits and the instrument reference point (gauge volume). At large distances, the slit system can lead to significant underestimation of the residual strain magnitude as well as poor definition of the gauge volume.
We show that for large specimens, the use of radial focussing collimators reduces these effects, leading to significant improvement in measurement reliability. Specifically, we show application of radial collimators at the SALSA instrument of the Institut Laue Langevin neutron source in Grenoble, France.
Kowari - OPAL's New Stress Diffractometer for the Engineering Community: Capabilities and First Results
Authors: Kirstein Oliver , Garbe Ulf , Luzin Vladimir
Published: June 2010

Kowari is a neutron diffractometer at ANSTO’s research reactor OPAL. The instrument is dedicated to investigate residual strains and stresses in engineering samples or new materials. Besides its usage in engineering/strain-scanning it is more and more frequently being used for obtaining texture information related to materials science applications. In particular the possibility of using the gauge volume defining slit systems allows extracting local information from the diffraction peak, i.e. position, intensity, and width, without the need to cut the sample specimen. The instrument obtained its operating license in August 2008 to briefly describe the instruments parameters and capabilities, and give examples of two typical applications since it went from commissioning into user mode.
A Challenge for a High-Resolution Ag-In-Cd Decoupler in Intensified Short-Pulsed Neutron Source
Authors: Kikuchi Kenji , Teshigawara Makoto , Harada Masahide , Saito Shigeru , Maekawa Fujio , Futakawa Masatoshi , Ishigaki Toru
Published: June 2010

A sharp pulsed-neutron beam, which has narrow width and large attenuation, will enhance ability to separate peak position diffracted from crystal structure in time-of-flight measurement method. Traditional technique to satisfy the request above is to use Boron for decoupling higher cut-off energy. Disadvantage, however, will be an excess formation of He bubbles and large heat deposition in the materials as a result of (n,α) reaction, particularly in a MW class of neutron source. Alternative is to use a material combination of Ag-In-Cd, which has different energies for resonance absorption and often used in the control rod of pressurized water reactors with cladding stainless steel. For application of this material to pulsed-neutron source a challenge is to make sandwiches structure with Al alloy because a moderator is made of this material from points of views of heat removing. Technically hot isostatic pressing was a choice and devoted to realize a bonding strength through R&Ds. Final product was set up to MLF /J-PARC and a successful resolution was observed in a powder diffractometer.
Aspire to Become TAKUMI - TAKUMI Present Status and Research Topics -
Authors: Harjo Stefanus , Aizawa Kazuya , Ito Takayoshi , Arima Hiroshi , Abe Jun , Moriai Atsushi , Sakasai Kaoru , Nakamura Tatsuya , Nakatani Takeshi , Iwahashi Takaaki , Kamiyama Takashi
Published: June 2010

The construction of The Engineering Materials Diffractometer, TAKUMI of J-PARC has been finished on March 2009, and the commissioning has been started from September 2008 being parallel with the final stage of the construction. In the commissioning, after checking the validity and the stability of the detectors and the data acquisition system, powder diffraction data of an austenitic steel alloy with 10 mm diameter without beam collimation (high intensity mode) was measured, and the resolution Δd/d of 0.4% was confirmed, as designed. Further commissioning was done also with 2 mm diameter of annealed piano wire with combination of beam collimation (high resolution mode), and the resolution Δd/d of less than 0.2% was confirmed to be achieved. TAKUMI adopted an event mode data recording method. It was found that the recording method is very useful to manipulate data as we like, for instance, detector range, time of flight binning width and time resolved data, even the experiment has been finished.
Phase Stability of Rare-Earth Based Mixed Oxides in Nano-Regime: Role of Synthesis
Authors: Shukla Rakesh , Tyagi A.K.
Published: June 2010

Synthesis plays an important role in the phase stabilization of unusual compounds. Of late, preparation of metastable compounds has gained a tremendous momentum due to unusual properties exhibited by them. In this article, we will discuss how by mere change in certain parameters of the reaction a metastable phase can be isolated using a soft chemical route. Surface energy induced stabilization are also observed wherein enhanced stability of the mixed oxides are observed in the nano-regime of the compound.
Anomaly in Thermal Stability of Nanostructured Materials
Authors: Nanda Karuna Kar
Published: June 2010

Understanding of the melting temperature of nanostructures is beneficial to exploit phase transitions and their applications at elevated temperatures. The melting temperature of nanostructured materials depends on particle size, shape and dimensionality and has been well established both experimentally and theoretically. The large surface-to-volume ratio is the key for the low melting temperature of nanostructured materials. The melting temperature of almost free nanoparticles decreases with decreasing size although there are anomalies for some cases. Superheating has been reported for some embedded nanoparticles. Local maxima and minima in the melting temperature have been reported for particles with fewer atoms. Another quantity that is influenced by large surface-to-volume ratio and related to the thermal stability, is the vapour pressure. The vapour pressure of nanoparticles is shown to be enhanced for smaller particles. In this article, we have discussed the anomaly in thermal stability of nanostructured materials.
Au-Si and Au-Ge Phases Diagrams for Nanosytems
Authors: Hourlier Djamila , Perrot Pierre
Published: June 2010

A thermodynamic study describing relative stability of different systems solid and liquid at equilibrium involved in the growth of semiconductor nanowires is reported. A number of stable and metastable phase diagrams, taking into account the size and the shape of condensed phases are calculated for the two binary systems Au-Si and Au-Ge.
Grain Growth Behavior of Al2O3 Nanomaterials: A Review
Authors: Gupta Ankur , Sharma Samir , Joshi Milind R. , Agarwal Parnika , Balani Kantesh
Published: June 2010

Emergence of engineering nanomaterials to render exceptional properties require understanding the thermodynamics and kinetics of grain growth and eliciting role of grain boundary mobility therein. Grain boundary mobility in alumina (Al2O3) has shown several repercussions on the evolution of microstructure to render drastic differences in the mechanical- (hardness, yield strength), optical- (transmittance), electrical- (conductivity), magnetic- (susceptibility), and electrochemical- (corrosion) properties. Consequently, the role of surface energy and the effect of temperature in equilibrating the grain shape and size are presented herewith. Several statistical or deterministic computational modeling have been attempted by researchers to elicit the dominating grain growth mechanisms. But, the limitations extend from the memory of computer and number of atoms in a simulation, or feeding the boundary conditions without incorporation of the initial microstructure to arrive at the dominating growth mechanism parameters. Contrastingly, the role of dopants in Al2O3 to either enhance or impede the grain growth is presented via various complexions responsible for transitions at the grain boundary interface. Six complexions resulting various grain boundary interface, strongly affect the grain boundary mobility, and sideline the dopant contributions in deciding the overall grain boundary mobility. It has also been presented that grain growth exponent increases with decreasing grain size, and additionally, secondary reinforcement of carbon nanotube (CNT) in Al2O3 impedes the grain mobility by as much as four times. The effect of temperature is found to be more pronounced, and has shown to enhance the grain boundary mobility by as much as six orders of magnitude.
Splicing and Coupling Losses in Hollow-Core Photonic Crystal Glass Fibers
Authors: Carvalho J.P. , Magalhães F. , Frazão O. , Santos J.L. , Araújo F.M. , Ferreira L.A.
Published: June 2010

Hollow-core photonic crystal glass fibers have a high potential for gas sensing applications, since large light-gas interaction lengths can be effectively attained. Nevertheless, in order to enhance effective diffusion of gas into the hollow-core fiber, multi-coupling gaps are often needed, which raise coupling loss issues that must be evaluated prior to the development of practical systems. In this paper, a study on the coupling losses dependence on lateral and axial gap misalignment for single-mode fiber and two different types of hollow-core photonic crystal glass fibers is carried out. In addition, an experimental technique on splicing these glass fibers is also described and some results are presented showing that low splice losses can be obtained with high reproducibility.
Application of Glass Reinforced Hydroxyapatite Composite in the Treatment of Human Intrabony Periodontal Angular Defects – Two Case Reports
Authors: Pavan Kumar G. , Jaya Kumar A. , Krishnanjaneya Reddy P. , Nandyala Sooraj Hussain , Lopes M.A. , Santos José D.
Published: June 2010

Bony defects caused by periodontitis are often treated by regenerative therapy using autografts and/or allografts. Alloplasts such as hydroxyapatite or ceramics and bioactive glasses are used as osteoconductive materials that serve as scaffold for new bony ingrowth. The purpose of this study was to ascertain the possible regenerative capability of glass reinforced hydroxyapatite (Bonelike¬)¬¬¬ an osteoconductive synthetic graft in the treatment of human periodontal intrabony angular defects. The material was placed in 2 defects in 2 individual patients and clinical parameters such as probing depth (PD) and clinical attachment level (CAL) have been included. Bone fill was determined using an intra oral periapical radiograph (IOPA) and Autocad Software. After 3 months implantation period, there was an improvement in CAL and reduction in PD along with bone fill was observed.
Molecular Mechanism of Water Oxidation Reaction at Photo-Irradiated TiO2 and Related Metal Oxide Surfaces
Authors: Nakamura Ryuhei , Nakato Yoshihiro
Published: June 2010

Recent studies on the molecular mechanism of water photooxidation (or oxygen photoevolution) reaction on TiO2 and related metal oxides or oxynitrides are reviewed. It is shown that a lot of experimental and theoretical studies give definite support to our recently proposed new mechanism, called “nucleophilic attack of H2O” or “Lewis acid-base” mechanism. The new mechanism has the prominent features that it possesses energetic and kinetics different from the conventional electron-transfer mechanism and can explain water photooxidation reaction on visible-light responsive metal oxides or oxynitrides, contrary to the conventional one. The result indicates that the new mechanism is useful for searching for new efficient visible-light responsive materials for solar water splitting.
Efficient Photoelectrochemical Splitting of Water to H2 and O2 at Nanocrystalline Carbon Modified (CM)-n-TiO2 Thin Films
Authors: Shaban Yasser A. , Khan Shahed U.M.
Published: June 2010

The carbon modified n-type titanium oxide (CM-n-TiO2) thin films were synthesized by flame oxidation of Ti metal sheets both flat and grooved and also by using combination of spray pyrolysis and flame oxidation of flat surface. Also undoped reference n-TiO2samples were also synthesized in an electric oven for comparison. Photoresponse of CM-n-TiO2 and n-TiO2 were evaluated by measuring the rates of water splitting to hydrogen and oxygen, in terms of observed photocurrent densities. Under the white light illumination of intensity of 100 mW cm-2 from the xenon lamp the photocurrent densities were found to be 1.60, 9.17, 11.44 and 14.68 mA cm-2 for optimized oven made n-TiO2 (sample1), flame made on flat surface (sample 2), on grooved surface (sample 3) and spray pyrolysis-flame made CM-n-TiO2 (sample 4) thin films at 0.477 V, 0.240 V, 0.242 V and 0.215 V biases respectively. The corresponding maximum photoconversion efficiencies for these thin films were found to be 1.2 %, 9.08 %, 11.31 % and 14.04 % for samples 1-4 respectively. Under monochromatic light illumination from the xenon lamp the maximum photoconversion efficiencies for samples 1-4 were found to be 0.94 %, 8.86 %, 11.16 % and 13.79 % respectively. However, under actual natural global AM 1.5 sunlight illumination of 1 sun, the maximum photoconversion efficiencies reduced to 0.67 %, 5.63 %, 7.62 % and 12.26 % for samples 1, 2, 4 and 3 respectively. These values compared well with those found under monochromatic light illumination from the xenon lamp. The increasing efficiencies were found consistent with lowering of band gaps from 2.9 eV for sample 1 to 2.65 eV and generation of mid-gap band at 1.6 eV for both samples 2 and 3 and 1.4 eV above the valence band for sample 4. Carbon contents were found to be 0.0, 17.60, 19.38 and 23.23 atom % for samples 1, 2, 3 and 4 respectively.
Sol-Gel Titania and Titania-Silica Mixed Oxides Photocatalysts
Authors: van Grieken Rafael , Aguado José , López-Muñoz María José , Marugán Javier
Published: June 2010

This paper presents a review of the work published by the authors on the synthesis, characterization and evaluation of the photocatalytic activity of TiO2/SiO2 materials. The use of titania-silica mixed oxides photocatalysts is proposed basically as a process improvement to overcome the difficulties of recovering titania from the slurries after the photocatalytic treatment of contaminated waters. To understand the mechanism governing the photocatalytic activity of these materials, several titania-silica photocatalysts have been prepared through a sol-gel method that allows controlling the main variables to obtain materials with different textural properties, degree of titania incorporation, dispersion of the photoactive phase and crystallinity of titanium dioxide. The samples have been characterized in depth, looking for correlations between the main physicochemical properties (TiO2 crystallite size, band gap energy and titania surface area) and the activity shown in the photocatalytic oxidation of cyanide, selected as model pollutant. The results suggest that the photocatalytic activity is strongly influenced by the quality of the titania crystal network, which in turn is improved by the use of a hydrothermal crystallization procedure. Additionally, the evaluation of the fraction of the total surface area corresponding to titania is mandatory for comparing the catalytic activity of different materials in processes in which titanium dioxide is the only phase catalytically active and silica behaves as an inert support.
An Overview of Semi-Conductor Photocatalysis: Modification of TiO2 Nanomaterials
Authors: Anandan S. , Ikuma Y. , Niwa K.
Published: June 2010

Since the beginning of life on earth, the environment has been polluted by waste, both natural as well as synthetic (man-made). In the case of natural waste however, the environment by itself controls the effect of contamination. But in the case of synthetic materials, the pollution is higher even in trace concentration and this may go on accumulating, leading to disastrous effects on the environment and ecology. Industrial wastes containing heavy metals and pesticide residues fall in this category. The major point sources of pesticide pollution are wastewater from agricultural industries and pesticide manufacturing and formulating plants. Hence the waste from these sources must be removed or destroyed before discharge to the environment. There have been several methods practiced for the treatment of wastewater. However many of them are not able to achieve hundred percent satisfaction.
Environmental pollution and destruction on a global scale as well as lack of sufficient clean and natural energy sources have drawn much attention and concern to the vital need for ecologically clean chemical technology, materials and processes. This is one of the most urgent challenges facing chemical scientists. Recently, light-induced photocatalytic reactions have gained a lot of attention for the purification of wastewater.
Photocatalytical Properties of TiO2 Nanotubes
Authors: Liang Hai Chao , Li Xiang Zhong , Nowotny Janusz
Published: June 2010

Titanium dioxide (TiO2) nanotubes have been reported one decade ago and have proven to be of a great interest in photocatalytic water splitting, as well as gas sensing and anti-bacterial/cancer treatment. This paper presents an overview on general preparation approaches (chemical treatment, template method and anodic oxidation) of tubular TiO2 nanoarchitectures and their characterization. Current applications of the nanotubes as photocatalysts are also reviewed.
Titanium Dioxide Photocatalyst - Unresolved Problems
Authors: Bak Tadeusz , Norby Truls , Nowotny Janusz , Nowotny Maria K. , Sucher Nikolaus
Published: June 2010

The present work considers the performance of TiO2-based photosensitive oxide semiconductors as photocatalysts for water purification. This paper brings together the concepts of solid state chemistry for nonstoichiometric compounds and the concepts of photocatalysis in order to discuss the reactivity between TiO2 and water including microorganisms (bacteria and viruses). The performance of TiO2 photocatalysts are considered in terms of a model of photoelectrochemical cell. The experimental data on photocatalytic removal of microorganisms from water are considered in terms of the effect of several properties, including pH, dispersion, light intensity, and temperature. It is argued that correct understanding of the performance of TiO2 photocatalysts requires recognition that properties of TiO2, which is a nonstoichiometric compound, are determined by defect disorder and the related ability to donate or accept electrons. The photocatalytic properties of TiO2 are considered in terms of the reactivity of both anodic and cathodic sites with water and the related charge transfer at the TiO2/H2O interface. It is shown that the formation of well defined photocatalysts requires knowledge of mass and charge transfer during processing and performance, respectively. The main hurdles in the development of high-performance photocatalysts are discussed.
Structure and Properties of the Melt-Spun Fe41Ni39P10Si5B5 Alloy Heat Treated at Elevated Temperatures
Authors: Ziewiec Krzysztof , Prusik Krystian
Published: June 2010

The aim of the work was to provide information on structure development and change of properties at elevated temperatures in Fe41Ni39P10Si5B5 amorphous alloy. The alloy was characterized by X-ray diffraction. The changes of properties were characterized with use of dynamic mechanical thermal analysis (DMTA) and the resistivity measurements at elevated temperatures. The microstructure of the melt spun ribbon was investigated with use of transmission electron microscope (TEM) at different stages of phase transformations after heating to different temperatures. The initially amorphous structure undergoes phase transformations due to glass transition and crystallization of the alloy. The appearance of glass transition region results in decrease of storage modulus and in a reversible change of temperature coefficient of resistivity (TCR). The phases are characterized with use of TEM. The crystallization was found to have the two stages. Formation of bcc crystals and Ni12P5 is followed by transformation of the products into fcc crystals and Ni3P. Temporary changes of the storage modulus and elongation of the sample suggest formation of hard phases during crystallization.
Characterization of β and Mg41Nd5 Equilibrium Phases in Elektron 21 Magnesium Alloy after Long-Term Annealing
Authors: Kiełbus Andrzej , Rzychoń Tomasz , Lityńska-Dobrzyńska Lidia , Dercz Grzegorz
Published: June 2010

The paper presents results of TEM and XRD investigations of Elektron 21 magnesium alloy in as cast condition and after long-term annealing at 250 and 350°C. In as cast condition Elektron 21 consists of primary α-Mg solid solution with α-Mg-Mg3RE eutectic and regular precipitates of MgRE3. Precipitation at 250 °C causes formation of the equilibrium β phase. Annealing at 350°C caused precipitation of globular Mg41Nd5 phases on solid solution grain boundaries. Also precipitates of MgRE3 phase have been observed.
Microstructure Formation in Austenitic Steel after Compression with Oscillatory Torsion Test
Authors: Rodak Kinga , Radwański Krzysztof
Published: June 2010

Different techniques have been used to introduce large strains into metals, for example torsion under pressure (HPT), cyclic extrusion compression (CEC), equal channel angular extrusion (ECAE), or accumulative roll bonding (ARB). Recent investigations are focused on analyzing new and alternative techniques for introducing severe plastic deformation (SPD) and to compare SPD techniques in terms of grain refinement and enhancement of properties. Compression with oscillatory torsion was applied to 0H18N9 austenitic steel to achieve a large strains. The microstructure was characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Formation of deformation twins and shear bands are responsible for the structure refinement in materials with low stacking fault energies (SFEs) such as austenitic steel. The investigations revealed, that nano-sized grains of 0H18N9 steel after processing by compression with oscillatory torsion are found in three different types of regions.
Structural Stability of Cu Processed by Severe Plastic Deformation Method
Authors: Rodak Kinga , Radwański Krzysztof
Published: June 2010

The annealing behaviour of monocrystaline Cu processed by Cyclic Extrusion Compression (CEC) was investigated. The effect of the CEC strain on the annealing behaviour of submicrometer grained structure was studied by examination of the microstructural changes of the samples processed by two different CEC strains, 4.8 and 13.9 during annealing at 300oC for the time in the range from 1sec to 120 min. The results show that microstructure is stable up to an annealing time of 15 min. At a higher time of annealing (above 15 min), a gradual grain growth occurs.
Structure and Properties of Cold-Worked and Annealed Ti-Ni-Co Shape Memory Wires Designed for Medical Application
Authors: Lekston Zdzisław , Stróż Danuta , Jędrusik-Pawłowska Magdalena
Published: June 2010

The effect of plastic deformation by drawing and rolling in the martensite state and final annealing on the structure, grain size, martensitic transformations and shape memory properties of TiNiCo wires is described in the paper. The wires were cold worked by 30 and 40% and then annealed at the temperature range 300-600oC. The structure, phase composition and transformation behaviour of samples after processing and annealing were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD) method and differential scanning calorimetry (DSC) technique. The marformed and annealed at 400 and 450oC wires exhibited a very good superelastic behaviour. The obtained wires were used for production of the shape memory staples with the recovery temperatures close to the human body temperature and as well as for small superelastic staples for fixation of mandible bone fractures.
Studies of Plastically Deformed Ni-Mn-Ga Ferromagnetic Shape Memory Alloy
Authors: Drdzeń Andrzej , Goryczka Tomasz , Prusik Krystian , Morawiec Henryk , Lelątko Józef
Published: June 2010

A polycrystalline ferromagnetic Ni2MnGa alloy with chemical composition of 49.13 at % Ni, 27.48 at % Mn and 23.39 at % Ga was hot rolled at 10000C causing deformation of 27%, 57% or 69%. The influence of the rolling process on the structure and texture of the parent phase were analyzed by EBSD and by X-ray powder diffraction methods. All samples revealed presence of the reversible martensitic transformation. During the solidification process columnar grains were formed with the <110>B2 texture. Sample deformation done by hot-rolling caused texture evolution from the <110> via <100> to the complete random distribution.
Orientation Mapping Study on the Inhomogeneous Microstructure Evolution during Annealing of 6013 Aluminum Alloy
Authors: Bieda-Niemiec M. , Sztwiertnia Krzystof , Korneva A. , Czeppe Tomasz , Orlicki R.
Published: June 2010

Orientation mapping in transmission electron microscope was successfully applied to study microstructural changes at the initial stage of recrystallization in the aluminum alloy with a bimodal second-phase particle distribution. The alloy samples were reversibly cold rolled resulting in the formation of laminar structure with zones of localized strain around large second-phase particles. Orientation mapping and in-situ investigations carry information about the processes which are active in the deformation zones during annealing.
Rolling Texture Formation in Super-Duplex Stainless Steel
Authors: Ryś Janusz , Ratuszek Wiktoria
Published: June 2010

The present research is a part of project which concerns a deformation behavior of duplex type ferritic-austenitic stainless steels. This paper focuses on the examination of ferrite and austenite textures formed upon thermo-mechanical treatment and deformation textures developed during cold-rolling of super-duplex stainless steel sheet. The character and stability of the textures observed in both phases over a wide deformation range are the result of two-phase morphology formed upon hot- and subsequent cold-rolling. The specific band-like morphology of the ferrite-austenite structure creates different conditions for plastic deformation due to the interaction of both phases and considerably constrained lattice rotations. That is why the processes governing the texture formation in duplex steels are supposed to change in comparison to single phase steels affecting final rolling textures of ferrite and austenite.
Microstructure and Deformation Behavior of Cold-Rolled Super-Duplex Stainless Steel
Authors: Ryś Janusz , Witkowska Małgorzata
Published: June 2010

The present examination is a part of project concerning a deformation behavior of duplex type ferritic-austenitic stainless steels. The investigations included the analysis of ferrite and austenite microstructures formed in cold-rolled sheet of super-duplex stainless steel, major deformation mechanisms operating in both constituent phases and changes in morphology of two-phase structure after the thermo-mechanical treatment and subsequent cold-rolling. Duplex type stainless steels develop the band-like ferrite-austenite morphology in the course of hot- and cold-rolling. This specific two-phase structure creates different conditions for plastic deformation in comparison to single phase steels. The interaction of both phases upon deformation exerts fairly significant influence on structure and texture formation in both constituent phases and in consequence affects the material properties and its behavior upon further processing.
Structure of Fe-Based Metallic Glass after Crystallization Process
Authors: Nowosielski Ryszard , Babilas Rafał , Dercz Grzegorz , Pająk Lucjan
Published: June 2010

The work presents a crystallization process of Fe-based amorphous alloy by characterization of the influence of annealing temperature on structural changes and magnetic properties of Fe72B20Si4Nb4 metallic glass. The studies were performed on the samples in the form of ribbons and rods. Crystallization behaviour of the studied alloy was examined by
X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. The studies of soft magnetic properties of tested material involved magnetic permeability, saturation induction, coercive field and magnetic after-effects measurements.
New, Experimental Powder Diffraction Data for Metastable Fe3B Phase Prepared According to ICDD Standards
Authors: Pająk Lucjan , Olszewska E. , Pikus Stanislaw , Dercz Grzegorz , Rasek Józef
Published: June 2010

In the present work X-ray studies were performed on annealed Fe78Nb2B20 amorphous alloy prepared by melt-spinning technique. All the samples were annealed in vacuum for 1 hour at temperatures up to 800°C. For the studied alloy -Fe and Fe2B are the stable, crystalline phases. The -Fe crystallized as the first crystalline phase in the sample annealed at 350°C. On the other hand, metastable Fe3B phase appeared to be stable during annealing in 425-800°C temperature range. The best fitting of the experimental X-ray data to as jet available ICDD files was obtained for Ni3P type structure (39-1315 – S.G.: I (82)). New, experimental powder diffraction data for metastable Fe3B phase prepared according to ICDD standards were elaborated for the sample annealed at 600°C. For this sample the best agreement between the calculated values of lattice constants and positions of experimental diffraction lines was obtained. The X-ray data were collected using X-Pert Philips diffractometer equipped with curved graphite monochromator on diffracted beam. The Treor program was applied for the analysis of X-ray diffraction data.
The Structure of Low-Temperature Tridymite in Silica Refractories
Authors: Podwórny J. , Zawada Justyna
Published: June 2010

The paper presents results of investigations aimed at determining the structure of low-temperature tridymite in refractory silica materials.
In the initial phase of works, the literature and Internet databases containing structural data of crystalline compounds were reviewed in search of a model of tridymite structure which best fits the one forming in silica materials. The results of reviewing the models of polymorphous tridymite forms which are available in the world literature have been verified by Rietveld method, using a sample of silica material that contained tridymite without cristobalite and residual quartz. On the basis of analyses it was found that tridymite in refractory silica materials occurs in a form of two low-temperature polymorphous forms C1 and F1, instead of one form – Cc, as it was assumed before.
The developed model has been used in a quantitative analysis (Rietvield method) of phase composition of several silica refractories.
The Mössbauer Spectroscopy and X-Ray Diffraction Studies of Phase Transformation during Tempering in High-Carbon Tool Steel
Authors: Bała P. , Krawczyk J. , Hanc Artur , Dercz Grzegorz
Published: June 2010

This work presents the results of investigations using Mössbauer spectroscopy technique and XRD, and their interpretation concerning precipitations and transformation of iron carbides and retained austenite stabilization. It also discusses changes in hardened matrix during tempering in relation to previously conducted dilatometric, microscopic and mechanical examinations. This research was carried out using a new high-carbon alloy 120MnCrMoV8-6-4-2 steel, which was designed in 1998, in Phase Transformations Research Group at the AGH UST. The influence of the tempering time on the mechanical and chemical stability of retained austenite and on the products of its transformation, nucleation and solubility of iron carbides and cementite nucleation and growth, was determined.
Influence of Manganese and Tin Substitution on the Structure and Magnetic Properties of CdCr2Se4
Authors: Jendrzejewska Izabela , Zajdel Paweł , Mroziński Jerzy , Maciążek Ewa , Goryczka Tomasz , Hanc Aneta , Kita Andrzej
Published: June 2010

Single phase materials with general formula CdxMeyCr2Se4 (where Me = Mn, Sn) were obtained using solid state synthesis method. Both compounds are ferromagnets with TC =115K (Sn) and 135K (Mn). The values of Curie-Weiss parameter ΘC-W = 135K (Sn) and 145K (Mn) are higher than respective values of TC indicating a presence of competing antiferromagnetic component. The values of lattice parameters are consistent with Sn and Mn replacing Cd. Slight cadmium deficiency has been also observed.
The X-Ray Studies and Magnetic Properties of Co0.83Fe1.8Se4
Authors: Maciążek Ewa , Goryczka Tomasz , Mroziński Jerzy , Jendrzejewska Izabela , Zawisza Beata
Published: June 2010

The polycrystalline Co0.83Fe1.8Se4 compound was obtained using ceramic method. The chemical composition was verified using energy-dispersive X-ray fluorescence spectrometry (EDXRF) and EDS method. X-ray analysis was used to make phase and structure analysis. The Rietveld method was applied for structure refinement. Co0.83Fe1.8Se4 compound crystallized in monoclinic system, space group C . The magnetic susceptibility and magnetization were measured, they revealed ferrimagnetic properties of a sample.
Magnetic and Electric Properties of FeNbB Melt Spun Ribbons
Authors: Stokłosa Z. , Pająk Lucjan , Lelątko Józef , Badura G. , Rasek Józef , Kwapuliński P. , Haneczok G.
Published: June 2010

In the paper Fe82Nb2B16, Fe80Nb2B18 and Fe78Nb2B20 amorphous alloys, obtained by melt spinning, were examined. It was shown that the alloys studied in the as quenched state and in the relaxed amorphous state or in nanocrystalline state (after a suitable annealing) belong to very good soft magnetic materials with relatively high resistivity. The influence of annealing on brittleness as well as magnetic and electric properties measured at room temperature was examined. A correlation between sample microstructure (in the as quenched state and after annealing) and different physical properties is discussed. It was shown that the observed changes of relative magnetic permeability can be explained by changes of magnetoelastic energy, concentration of microvoids frozen during production process, effective anisotropy constant and magnetic polarisation.
Thermal Expansibility of 310S Steel-Based PVD Coating in Presence of Metastable Phase
Authors: Kucharska Barbara
Published: June 2010

The paper discusses the examination of the thermal expansibility of a coating composed of the austenitic steel 310S using the X-ray diffraction technique. Temperature measurements were made in the temperature interval of Tamb200°C, in which the transition of the metastable bcc phase forming the as-applied coating into an fcc-type phase occurred in the coating. The values of the coefficients of thermal expansion of both phases were determined by using the weighted average of the intensities of diffraction reflections recorded. The values of the coefficients of thermal expansion of both phases within the entire examination range (Tamb200°C), determined as the weighed averages with the weight allowing for the intensities of individual reflections, were found to be, respectively, 0.910-5 K-1 for the bcc phase and 1.510-5 K-1 for the fcc phase, and by approx. 0.110-5 K-1 lower than the values typical of the phases of austenite and ferrite in conventional steels.
High Temperature Study of Metamict Steenstrupine
Authors: Kusz Joachim , Malczewski Dariusz , Zubko Maciej , Häger T. , Hofmeister W.
Published: June 2010

Metamict minerals contain radioactive elements that degrade their crystal structure. Unlike other metamict minerals, annealing process under ambient pressure do not lead to direct recrystallization of steenstrupine.
X-Ray Topography Study of the Nickel Superalloy CMSX-4 Single Crystals
Authors: Onyszko Arkadiusz , Bogdanowicz Włodzimierz , Kubiak Krzysztof , Sieniawski Jan
Published: June 2010

The paper attempts to determine structural perfection of monocrystalline nickel superalloys using X-ray topography. Monocrystalline bars and turbine blades were manufactured in an ALD Vacuum Technologies furnace using the Bridgman method. Pulling out rates typical for CMSX-4 nickel superalloys were used. It has been found that in the case of monocrystalline bars the structural perfection determined based on X-ray topograms does not depend on the distance from the selector. Instead, for blades the structural perfection significantly decreases with increasing distance from the selector.
Characterisation of Phase Transition in Strontium Barium Niobate by Bond Method
Authors: Wokulska Krystyna , Pacek Paweł , Dec Jan , Łukasiewicz Tadeusz , Świrkowicz M.
Published: June 2010

The high quality Sr0.61Ba0.39Nb2O6 (SBN61) single crystals without any striations were obtained by Czochralski pulling method. The temperature dependence of the lattice parameters of the investigated crystals was studied using a precision X-ray Bond's method. The angular precision of the goniometer 1 arcsine and metric value of Cu K1 (λ = 1.54059292Å) allowed to obtain high precision and accuracy of lattice parameter measurements. The received results allowed to determine the Curie temperature and character of the phase transition in this material. The lattice parameter a monotonically increases and shows hardly visible inflection point at TC when increasing the temperature. The temperature dependence of the lattice parameter c displays quite distinct temperature behaviour. Contrastingly, it decreases with increasing the temperature experiencing an evident anomaly in the vicinity of the structural phase transition point. Obtained value of the ferroelectric phase transition point is TC = 346 ± 3K.
Complex Intermetallics in the Al-Rich Part of Al-Pd-Cr System
Authors: Kowalski W. , Grushko B. , Bogdanowicz Włodzimierz , Surowiec M.
Published: June 2010

The Al-Pd-Cr alloy system was investigated at 680 to 990°C in the compositional range above 60 at.% Al. The binary Al-Cr , μ and phases dissolves up to 1 at.% of Al, the η-phase extends up to 2 at.% of Pd and the 2-phase extends up to 3 at.% of Pd, respectively. The binary Al-Pd -phases dissolves up to 3 at.% of Cr and -phase up to 4 at.% Cr. Close to the high-Pd limit of the -range a ternary phase is formed between about Al78Pd4Cr18, Al77Pd10Cr13 and Al74Pd7Cr19. Its structure is orthorhombic with lattice parameters: a = 1.47, b = 1.24 and c = 1.25 nm, resembling the lattice parameters of the high-temperature Al3Mn phase. A hexagonal structure with a = 1.77 and c = 1.25 nm resembling Al-Ni(Cu)-Cr ζ-phase [1-3] was revealed around Al81.5Pd1.5Cr27 and another hexagonal structure with very close lattice parameters around Al73Pd11Cr16. Another ternary phase was found in 970°C around the Al77.5Pd1.5Cr21 composition. It has orthorhombic structure with a = 1.24, b = 3.46 and c = 2.04 nm resembling the ternary -phase in Al-Ni-Cr. An additional orthorhombic phase with a = 2.48, b= 3.87 and c = 2.04 nm was found to be formed between about Al82Pd4Cr14, Al79Pd4Cr17 and Al79Pd9Cr12.
The X-Ray Measurement of the Thermal Expansibility of Al-Si Alloy in the Form of a Cast and a Protective Coating on Steel
Authors: Kucharska Barbara , Wróbel A. , Kulej Edyta , Nitkiewicz Zygmunt
Published: June 2010

The paper presents the investigation of the expansibility of an Al-Si alloy in the form of a protective coating applied on a steel substrate and as a conventional cast, respectively. Examinations were carried out in the temperature range of troom÷220°C using the diffractometric technique based on reflections (311), (222), (400), and (331) from the Al solid solution. It was demonstrated that the coating exhibited better thermal expansibility compared to the cast, and its thermal expansion coefficient was close to the standard values for alloys of the same chemical composition. For the cast, the thermal expansion coefficient was lower by approx. 25% in relation to the standard value. It was also found that the soaking of alloys during X-ray examination reduced their texturing and caused changes in the microstructure of both the coating and the cast by thinning the silicon crystals and rounding their edges.
A Comparative Study on the Cu/Ni Multilayer Period Using Two X-Ray Wavelengths
Authors: Kucharska Barbara , Kulej Edyta , Kanak Jarosław
Published: June 2010

This paper presents the results of X-ray research on the structure of Cu/Ni multilayers magnetron-deposited on a Si (100) substrate. The multilayers, each consisting of a hundred Cu/Ni double-layers, but with a variable thickness of the Ni (1,2÷3nm) sublayer, were investigated. The thickness of the Cu sublayer was the same for all multilayers investigated and equalled 2nm. X-ray measurements were taken using filtered radiation with λCu=0.15405 nm and λCo=0.17902nm. The coatings were examined in respect of the angle at which the (111) reflection and satellite peaks appeared together. The obtained reflections were fitted using the Pseudo Voight curves. The thickness of the multilayer periods, resulting from the analysis of the diffraction pattern obtained for the above wavelengths of radiation, was compared. The thicknesses closest to those assumed in the deposition process were obtained for multilayers examined using radiation with Cu and utilizing the position of both satellite peaks, and multilayers examined using radiation with Co and utilizing the position of the main Cu/Ni(111) reflection and the S-1 satellite reflection.
Phase Transformation in Austenitic Steel Induced by Plastic Deformation
Authors: Drahokoupil Jan , Haušild Petr , Davydov Vadim , Pilvin P.
Published: June 2010

Kinetics of deformation induced martensitic transformation in metastable austenitic AISI 301 steel was characterized by several techniques including classical light metallography, X-ray diffraction, neutron diffraction and electron back scattered diffraction. In order to characterize the martensitic transformation, several specimens were tensile pre-deformed to 5%, 10% and 20% of plastic deformation and compared with non-deformed state. During straining, the volume fraction of α’-martensite rapidly prevails over the volume fraction of original austenite and reach the value circa 70%.
A Study of Point Defects in the B2-Phase Region of the Fe–Al system by Mössbauer Spectroscopy
Authors: Jabłońska Magdalena , Hanc Aneta , Szostak Anna
Published: June 2010

In this work, we employed the Mössbauer spectroscopy in a study of point defect formation in intermetallic phases of the B2 structure from the Fe-Al system as a function of Al concentration. We present the values of the 57Fe isomer shift and quadruple splitting for the components describing the point defect in the local environment of a Mössbauer nuclide. The concentration of the Fe vacancies and Fe atoms substituting Al (Fe-AS) are determined. The results shown that an increase in Al content causes an increase in vacancy and Fe-AS
The Microstructure of Rapidly Solidified Al-Zn-Mg-Cu Alloys with Zr Addition
Authors: Lityńska-Dobrzyńska Lidia , Ochin Patrick , Góral Anna , Faryna Marek , Dutkiewicz Jan
Published: June 2010

The effect of rapid solidification on the microstructure of Al-Zn-Mg-Cu alloys with 8 wt.% Zn-2 wt.% Mg-2.3 wt.% Cu and 0.2 or 0.5 wt.% of Zr additions were investigated using X-ray diffraction measurements (XRD), scanning (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X-ray (EDX) microanalysis. Rapidly solidified ribbons with thickness of 70-100 m were performed by melt spinning technique. The mould cast alloys as well as the melt spun ribbons revealed dendritic microstructure of (Al) solid solution and η Mg(Zn,Cu)2 phase in interdendritic areas. The refinement of the microstructure and reduction of the volume fraction of the η phase up to 1.7%, as compared to 4% in the mould cast alloys was observed in the ribbons. Copper dissolution up to about 20 wt % in the η phase causes a decrease of the lattice parameters. The Al3Zr primary precipitates were observed in the mould cast alloy containing 0.5 wt % of Zr while in the ribbons all zirconium dissolved in the aluminium solid solution.
Spin State Transition Studied by Means of Optical Microscope
Authors: Zubko Maciej , Zajdel Paweł , Kusz Joachim
Published: June 2010

We have tested a new method which allows assigning the spin state of the spin crossover (SCO) crystal in-situ during the diffraction experiment. The method is based on the analysis of change of the colour of the SCO compounds. We have found that the off-line setup in transmission geometry is reliable in assigning the magnitude of high spin molecules fraction (γHS) and the character (one step, many steps, histeresis) of the SCO transition. Later on, this method has been used in the in-situ measurements directly on X-ray four-circle diffractometer.
Mesoporous Ordered Organosilicas Containing Zr and Ti Species
Authors: Zienkiewicz M. , Pikus Stanislaw , Olszewska E. , Barczak M.
Published: June 2010

Periodic mesoporous organosilica materials (PMOs) are the new class of porous and hybrid organic-inorganic materials. They represent exceptional and functional bridged polysilsesquioxanes prepared by sol-gel processing of monomers using triblock copolymers or ionic surfactants as the structure directing agents. By changing the monomer type, various organic functional groups may be incorporated into the framework of PMO materials. Moreover it is possible to introduce heteroatoms in the structure of mesoporous materials via isomorphous substitution of the silicon atoms. In the present study, we report the preparation and characterization of the series of zirconium, titanium and mixture of them, doped mesoporous silica. The PMOs have been synthesized by the hydrolysis and the condensation of bridged silsesquioxane precursors containing two different organic bridging groups ((R’)3Si-CH2-CH2-Si(R’)3, R’ - methoxy or ethoxy). The influence of temperature of synthesis on the structure of PMOs was examined. PMO-Zr and PMO-Zr-Ti were synthesized by employing a zirconyl chloride octahydrate (ZrOCl2•8H2O), titanium isopropoxide, NaCl, bis(trimethoxysilyl)ethane (BTME) as a silica source and triblock copolymer P123 as the structure directing agent while PMO-Ti was prepared using 1,2-bis(triethoxysilyl)ethane (BTESE), titanium isopropoxide, NaOH and cetyltrimethylammonium bromide (CTABr) as a structure directing agent. The resulting materials exhibited well-ordered two-dimensional hexagonal space group p6mm, high surface areas in the range of 700-1100 m2/g. The X-ray photoelectron spectroscopy (XPS) analysis indicated the successful incorporation of heteroatoms into hybrid PMOs and the IR spectra confirmed satisfactory removal of the surfactants.
Surface Layers' Real Structure of Metals Exposed to Inhomogeneous Thermal Fields and Plastic Deformation
Authors: Pala Zdenek , Ganev N. , Drahokoupil Jan , Sveshnikov Alexej
Published: June 2010

Inhomogeneous thermal fields and plastic deformation are two basic phenomena present during surface creation and substantially determine future real structure of the surface layers. In the following, a closer look will be taken at some aspects connected with real structure of milled and ground steels. Impact of end-mill speed and thickness of removed layer on grain size, macroscopic and microscopic residual stress is discussed. Possibility of prestrained surface layer in ground steel has been examined on a set of five types of steels.