実験報告書様式（元素戦略）（ ※本報告書は英語で記述してください。ただし、産業利用課題として採択されている方は日本語で記述していただいても結構です。 ）Experimental Report

承認日 Date of Approval 4/18/2014
承認者 Approver Ryoichi Kajimoto
提出日 Date of Report; April 17, 2014

課題番号 Project No.

装置責任者 Name of Instrument scientist

2013S0003

Ryoichi Kajimoto

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Neutron-scattering research on element-strategy project for

4SEASONS (BL01)

electronic materials

実施日 Date of Experiment

実験責任者名 Name of principal investigator[1] 5/8 21:00-5/10 17:00, 2013; C12A7

Youichi Murakami[2] 3/3 11:00-3/5 9:00, 2014; Fe pnictide

所属 Affiliation
Institute of Materials Structure Science, KEK
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
[1] Name of sample: Inorganic electride C12A7.
Chemical formula: [Ca24Al28O64]・2O.
Form of shape: Single-crystal plates with (111)-surface cutting.
Quantity: (1010t1) mm3 4 pieces for a non-doped sample (Fig. 1), and2 pieces for an electron-dopedsample.
[2] Name of sample: Deuterium-doped lanthanum iron pnictide.
Chemical formula: LaFeAsO0.9D0.1.
Form of shape: Powder (wrapped in an Al foil with cylindrical shape, φ1640 mm).

Quantity: 30 g.
Physical property: Superconducting-transition temperature, Tc = 27 K.

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

Instrumental configuration of 4SEASONS[1] C12A7
Chopper speed; 200 Hz.

Ei; 120 meV.
MLF beam power; 300 kW.
Temperature; 290 K.
[2] Fe pnictide
Chopper speed; 150 Hz.
Multi Ei; 271, 44.1, 17.5, and 9.27 meV.
MLF beam power; 300 kW. (beam stop 3/4 19:15- 3/5 0:20, 5 h)Fig.	 1.	 Single	 crystals	 of	 C12A7	 (non-doped)	  aligned	  for	  the	 present	 INS	 experiment.	 

Temperature; 4, 8, 10, 15, 20, 25, 30, 35, 40 and 60 K.
Results[1] C12A7
Because of three-dimensional phononic properties, one needs to pile up several trajectories to extract
intensity-contour maps in (Q , ω) space. Therefore, we carried out a sequential scan by rotating the crystal
angle over 40

with 1step. At present, we have no quantitative data to analyze the low-energy phonon

dispersion, because the neutron intensity scattered inelastically was too weak to extract any phonon crosssections. The small sample volume (0.4 cc) together with the relatively short measuring time (0.5 hours foreach shot) could be the reason of the weak intensity.
[2] Fe pnictide
Figure 2(A) shows energy profiles at Q = 2.0 Å-1 measured at 4 K well below Tc and 40 K above Tc, in which
each data point represents the value integrated in Q over 1.7-2.3 Å-1. In addition to a peak at 11 meV (greenarrow), a gap-like structure appears significantly below 5 meV at 4 K. The 11-meV peak intensity begins toincrease below around Tc, as shown in the thermal evolution of Fig. 2(B). Hence, we infer that the gap-likefeature below 5 meV and the intensity enhancement at 11 meV are closely coupled and possibly related to theemergence of superconductivity. Note that no such the dynamic features were reported in the past papers
dealing with F-doped LaFeAsO system. The x dependence of S(Q, ω) will shed a light on the relationshipbetween the superconductivity and the dynamics of doped deuterium.

2. 実験方法及び結果（つづき） Experimental method and results (continued)

Fig. 2. (A) Energy profiles at Q = 2.0 (of the peak intensity at 11 meV.

0.3) Å-1 for T = 4 K (blue) and 40 K (ref). (B) Temperature dependence