実験報告書様式（一般利用課題・成果公開利用）

MLF Experimental Report

提出日 Date of Report
July 4, 2011
装置責任者 Name of responsible person

課題番号 Project No.

Takashi Kamiyama

2010B0025

装置名 Name of Instrument/（BL No.）

実験課題名 Title of experiment
Structural study of TbPd1-xNixAl with isostructural phase

BL-08
実施日 Date of Experimenttransition
実験責任者名 Name of principal investigator

Feb. 4 – Feb. 6, 2011

Hideaki Kitazawa
所属 Affiliation
National Research Institute for Materials Science (NIMS)
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.

TbPd1-xNixAl ( x = 0, 0.2, 0.4, 0.6, 0.8, 1.0 ) and TbNi1-xCuxAl ( x = 0.2, 0.3, 0.4 ) samples wereprepared by arc melting stoichiometric mixtures of the pure elements (Tb:3N; Pd: 3N5; Ni: 4N;
Cu:4N; Al:5N) in an argon gas atmosphere. The as-cast buttons were pulverized by an agate
mortal. All powder samples were checked by the X-ray diffraction to be single phase of thehexagonal ZrNiAl-type structure ( P6-2m ). The powder sample of 8.1 g to 9.9 g was filled in avanadium cylinder with 10 mm in outer diameter and 25 mm to 33 mm in length.

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.

2-1. Experimental methods

We have performed the powder neutron diffraction measurements using a high-resolution
neutron diffractometer, BL-08 (SuperHRPD) installed at the megawatt-class pulsed spallation
neutron sources, J-SNS, at the Japanese particle accelerator research complex (J-PARC). The
exposure time for data collection in 0.2 MW operation was approximately 5 hours for each sample
contained in a cylindrical vanadium cell 10 mm in outer diameter. Rietveld refinements werecarried out using the program Z-Rietveld ver. 0.9.36 for time-of-flight neutron powder diffraction
analyses.
All the diffraction peaks could be indexed by the the hexagonal ZrNiAl-type structure ( P6-2m ).
When we tried to fit all powder patterns by Z-Rietveld, we could find the tentative structure parametersat room temperature as shown in the Table 1 and 2. The nominal concentration was fixed in theprocess of Riedveld analysis for simplicity. However, we could not achieve further reduction of1

2. 実験方法及び結果（つづき） Experimental method and results (continued)
Table 1 Tentative structure parameters of TbPd1-xNixAl at room temperature with a single phase fitting.
xa (Å)c (Å)

c/aRwp (%)

07.19178(2)3.99425(2)0.55539

6.3

0.2

7.11500(0)4.01527(1)0.56434

8.0

0.4

7.04986(1)4.02518(1)0.570956.6

0.6

7.01000(0)4.00235(1)0.570958.8

0.8

7.017592(6)3.931178(6)0.560197.1

1

7.00613(1)3.87749(1)0.55344

6.6

Table 2 Tentative structure parameters of TbNi1-xCuxAl at room temperature with a single phase fitting.
xa (Å)c (Å)

c/a

Rwp (%)

07.00613(1)3.87749(1)0.55344

6.6

0.2

7.022901 (3)3.898384 (4)0.564345.8

0.36.978217 (7)3.967262 (9)0.5685210.8

0.4

7.01000(0)4.00235(1)0.57095

6.3

the R-factor. One reason is that the alloying transition element of Ni or Cu for Pd or Ni,
respectively, induces the isostructural phase transition (IPT). When we apply the empirical rulethat the IPT appears in the forbidden range of c/a from 0.56 to 0.57, IPT should occur at around x= 0.2 and 0.8 in TbPd1-xNixAl and x = 0.2 - 0.3 in TbNi1-xCuxAl, respectively. The double peaks of(210) peak in Fig.1 indicate that the 2 phases with low and high c/a ratio clearly coexist inTbPd1-xNixAl. The two phases coexist at around x = 0.3 in TbNi1-xCuxAl as shown in Fig.2. We
could detect the coexistence of both phases owing to the high resolution neutron diffractometer,
BL-08 (SuperHRPD). We need further investigation with different concentration of Ni and Cu todescribe the whole phase diagram.
50

20

10x=0x = 0.2x = 0.3x = 0.4
x=02 -1 0TbNi1-xCuxAl1013015Intensity ( a. u. )Intensity ( a. u. )x=0
x = 0.2
x = 0.4
x = 0.6
x = 0.8
x = 1.0

TbPd1-xNixAl(201) reflection

4051000
2.38

2.40

2.42

2.44

2.46

3.2

2.48

Fig. 1

Ni concentration dependence of a (201)

Bragg peak position in TbPd1-xNixAl.

3.3

3.5

3.4

3.6

3.7

d(Å)

d(Å)

Fig. 2 Ni concentration dependence of (1 0 1) and(2-1 0) Bragg peak position in TbNi1-xCuxAl.

2