Superconductivity, long-range magnetic order and crystalline-electric field effects in ternary rare earth compounds

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5456630

Woolf, L D

Results of an extensive calorimetric investigation of ternary are earth compounds such as RERh/sub 4/B/sub 4/ and RE/sub 1/ /sub 2/Mo/sub 6/S/sub 8/ and related pseudoternary systems was undertaken to study the competing mechanisms o superconductivity and magnetism. Heat capacity data were collected in zero and various applied magnetic fields for LuRh/sub 4/B/sub 4/ and in zero field for YRh/sub 4/B/sub 4/. A modified Debye model as well as a molecular crystal model were employed to describe the normal state data. Various superconducting and normal state parameters were derived. Spike-shaped features superimposed on top of a broader anomaly in the heat capacity of ErRh/sub 4/B/sub 4/ and Ho/sub 1/ /sub 2/Mo/sub 6/S/sub 8/ were observed at reentrant transitions, and the effects of external magnetic fields on this reentrant transition were investigated. Pronounced discontinuities in the specific heat at the magnetic ordering temperatures were apparent for the RERh/sub 4/B/sub 4/ compounds where RE = Gd,Tb,Dy, and Ho, and the contribution of ferromagnetic transitions to the specific heats of these compounds is discussed. Phase diagrams were constructed which delineate the paramagnetic, superconductivity, magnetically ordered and normal, and magnetically ordered and superconductivity regions. Crystal field effects were also investigated for both types of compounds. (BLM)

• Research Organization: California Univ., San Diego (USA)
• OSTI ID: 5456630
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORIDES
BORON COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MAGNETISM
MOLYBDENUM COMPOUNDS
MOLYBDENUM SULFIDES
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
RHODIUM BORIDES
RHODIUM COMPOUNDS
SPECIFIC HEAT
SULFIDES
SULFUR COMPOUNDS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS