Pyrochlore solid solutions (La/sub x/Y/sub 1-x/)/sub 2/Mo/sub 2/O/sub 7/, x = 0. 0 to 0. 5. Spin-glass-like behavior

Journal Article · Wed Apr 01 00:00:00 EST 1987 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(87)90360-4· OSTI ID:6544164

Sato, M; Greedan, J E

The (La/sub x/Y/sub 1-x/)/sub 2/Mo/sub 2/O/sub 7/ system was investigated in the range x = 0.0 to x = 0.5. Single-phase materials exist up to x = 0.4; the x = 0.5 composition has a small impurity contamination. The lattice constants are linear with x and range from 10.224 A (x = 0.0) to 10.461 A (x = 0.5). These lattice constants span the same range as the R/sub 2/Mo/sub 2/O/sub 7/ series from R = Y to R = Nd. In this series, there is a discontinuous change from ferromagnetic long-range order to short-range spin-glass-like order between R = Gd and R = Tb. Yet, the solid solutions all show spin-glass-like properties with maxima in the susceptibility in the 20-25 K range and sample-history-dependent effects at lower temperatures. Deviations from the Curie-Weiss Law occur well above the susceptibility maxima. The Weiss constants change from -61 to + 41 K for x = 0.0 and x = 0.5, respectively, indicating a competition between antiferromagnetic and ferromagnetic exchange interactions. This competition, coupled with the inherent frustration of the Mo/sup 4 +/ lattice in space group Fd3m is a possible origin of the spin-glass properties.

• Research Organization: McMaster Univ., Hamilton, Ontario
• OSTI ID: 6544164
• Journal Information: J. Solid State Chem.; (United States), Vol. 67:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
LANTHANUM OXIDES
CRYSTAL STRUCTURE
MAGNETIC SUSCEPTIBILITY
SPIN GLASS STATE
MOLYBDENUM OXIDES
YTTRIUM OXIDES
EXPERIMENTAL DATA
LATTICE PARAMETERS
SPACE GROUPS
CHALCOGENIDES
DATA
INFORMATION
LANTHANUM COMPOUNDS
MAGNETIC PROPERTIES
MOLYBDENUM COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies