Development of pressure cell for specific heat measurement at low temperature and high Magnetic field.
We report the performance of Ag-Pd-Cu alloy as the material of a pressure cell to carry out specific heat measurements at low temperatures and high magnetic fields. The Ag-Pd-Cu alloy is advantageous to reduce the background due to the nuclear specific heat in the pressure cell growing at low temperatures and high magnetic fields. We prepared 70-20-10 alloy composed of 70 mass % of Ag, 20 mass % of Pd, and 10 mass % of Cu. The maximum hardness over 100 HRB (Rockwell-B scale) is achieved by the heat treatment. The magnetization and susceptibility results show that the alloy includes a small amount of magnetic ions, whose concentration is smaller than that in the Be-Cu alloy. We confirm that the specific heat of a piston cylinder cell made of the 70-20-10 alloy increases smoothly from 0.2 to 9 K and the nuclear specific heat decreases drastically in magnetic field compared to that expected in the Be-Cu alloy. The pressure value in the cell at low temperature increases almost linearly up to P=0.4 GPa, which is nearly the limit of the inner piston made of the 70-20-10 alloy, with increasing of the load applied at room temperature.
Kawae
T
T
Department of Applied Quantum Physics, Faculty of Engineering, Kyushu University, Motooka, Nishi-Ku, Fukuoka 819-0395, Japan. kawaetap@mbox.nc.kyushu-u.ac.jp
Yaita
K
K
Yoshida
Y
Y
Inagaki
Y
Y
Ohashi
M
M
Oomi
G
G
Matsubayashi
K
K
Matsumoto
T
T
Uwatoko
Y
Y