SPring-8, the large synchrotron radiation facility

Inquiry number

SOL-0000001098

Beamline

BL10XU (High Pressure Research)

Scientific keywords

A. Sample category	inorganic material
B. Sample category (detail)	superconductor
C. Technique	X-ray diffraction
D. Technique (detail)	powder diffraction
E. Particular condition	high pressure (DAC), low-T (~ liquid He)
F. Photon energy	X-ray (4-40 keV)
G. Target information	crystal structure, phase transition

Industrial keywords

level 1---Application area	others
level 2---Target
level 3---Target (detail)
level 4---Obtainable information	d-spacing (lattice parameter), valence, elastic modulus
level 5---Technique	diffraction

Classification

M10.20 powder diffraction

Body text

The isothermal equation of state of CeCu₂Ge₂ at 10K has been studied up to 20 GPa in a diamond anvil cell at BL10XU. Figure shows volume compression of a unit cell and pressure dependence of the superconducting transition temperature Tc. At 15 GPa , an anomalous contraction of the volume was observed while the crystal structure remained unchanged. This observation along with considerations is for the valence-change model for the origin of the pressure-induced Tc maximum in CeCu₂Ge₂.

Figure. Volume compression of a unit cell and pressure dependence of Tc in CeCu₂Ge₂

[ A. Onodera, S. Tsuduki, Y. Ohishi, T. Watanuki, K. Ishida, Y. Kitaoka and Y. Onuki, Solid State Communication 123, 113-116 (2002), Fig. 2,
©2002 Elsevier Science Publisher ]

Source of the figure

Original paper/Journal article

Journal title

Solid State Communication, 123(2002)113

Figure No.

2

Technique

The He flow type cryostat for the DAC can be mounted on the BL10XU's diffractometer for low temperature experiments down to 10 K as shown in figure. Combining the on-line pressure measurement system described above with a He-gas driven DAC, in which the pressure can be controlled remotely, one can conduct high- pressure experiment at low temperature very efficiently.

Figure. Cryostat mounted on BL10XU's diffractometer.

Source of the figure

Presentation material for Beamline Report

Required time for experimental setup

1 shift(s)

Instruments

Instrument	Purpose	Performance
DAC cryostat	high pressure/low temperature	70GPa, 10K

References

Related experimental techniques

electric conductivity under pressure

Questionnaire

This solution is an application of a main instrument of the beamline.

Ease of measurement

Middle

Ease of analysis

Easy

How many shifts were needed for taking whole data in the figure?

Two-three shifts