Thermal properties of (Dy{sub x}Gd{sub 1-x}){sub 3}Ga{sub 5}O{sub 12} garnet single crystals

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Advances in Cryogenic Engineering

OSTI ID:476736

Numazawa, T; Kimura, H; Maeda, H ^[1]

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1. Tsukuba Magnet Labs., Tsukuba (Japan); and others

The solid solution (Dy{sub x}Gd{sub 1-x}){sub 3}Ga{sub 5}O{sub 12} garnet is proposed as a high heat capacity material below 2 K for regenerator. A short range order interaction resulting from the magnetic frustration in Gd{sub 3}Ga{sub 5}O{sub 12} gives a considerably high heat capacity below 2 K. At a magnetic field B = {approximately}1 T, Gd{sub 3}Ga{sub 5}O{sub 12} has a sharp anomaly in its specific heat at {approximately}0.37 K related to an antiferromagnetic transition, keeping the large heat capacity. By substituting Gd ion by Dy ion, an anisotropy will be produced in (Dy{sub x}Gd{sub 1-x}){sub 3}Ga{sub 5}O{sub 12} and it enhances the antiferromagnetic long range order interactions. The specific heat measurement for (Dy{sub 0.5}Gd{sub 0.5}){sub 3}Ga{sub 5}O{sub 12} at B = 0 T showed that heat capacity of (Dy{sub 0.5}Gd{sub 0.5}){sub 3}Ga{sub 5}O{sub 12} is comparable largely to that of Gd{sub 3}Ga{sub 5}O{sub 12} and a transition temperature may be found below 0.6 K. From the thermal conductivity measurement, a strong correlation with magnetic field has been found. The reduction in the thermal conductivity caused by the magnetic field is the largest in Dy{sub 3}Ga{sub 5}O{sub 12} and it decreases by increasing the concentration of Gd ion.

• OSTI ID: 476736
• Report Number(s): CONF-950722--
• Journal Information: Advances in Cryogenic Engineering, Journal Name: Advances in Cryogenic Engineering Vol. 42A; ISSN ACYEAC; ISSN 0065-2482
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
DYSPROSIUM COMPOUNDS
GADOLINIUM COMPOUNDS
GALLIUM OXIDES
GARNETS
MAGNETIC PROPERTIES
MAGNETIC REFRIGERATORS
SPECIFIC HEAT
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES