Superconductivity and long range magnetic order in ternary rare earth transition metal borides

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6787885

Horng, H E

The close correlation between superconductivity, magnetic order and structural features is demonstrated with the study of the pseudoternary systems Er(Rh/sub 1-x/Ru/sub x/)/sub 4/B/sub 4/, Y(Rh/sub 1-x/Ru/sub x/)/sub 4/B/sub 4/ and (Lu/sub 1-x/Er/sub x/)RuB/sub 2/. The systematic investigation of the role of each atom in the particular ternary boride structure is addressed by low temperature measurements of electronic, transport and magnetic properties as well as by metallurgical methods. An abrupt depression of T/sub c/ versus transition metal concentration occurs at x approx. = 0.50 after a plateau with T/sub c/ approx. = 7.7K in the Er(Rh/sub 1-x/Ru/sub x//sub 4/B/sub 4/ pseudoternary system. Superconductivity and long range magnetic order both occur, but are exclusive of each other in this Er-based system. The superconducting-normal state boundary in the low temperature phase diagram is determined for the isostructural, nonmagnetic system Y(Rh/sub 1-x/Ru/sub x/)/sub 4/B/sub 4/. From single crystal x-ray diffraction data, the size of the transition metal clusters and intercluster distances are related to the occurrence of superconductivity. Particular emphasis is placed on the orthorhombic (Lu/sub 1-x/Er/sub x/)RuB/sub 2/ system which exhibits reentrant superconductivity. Two distinct magnetic transitions are observed for samples in the concentration range, 0.5 less than or equal to x less than or equal to 1. Heat capacity, upper critical field and resistivity data for samples in this system are measured in order to study the competition between superconductivity and magnetic order. A high Debye temperature (487K), modified Debye model and BCS theory provide an excellent description of the superconducting (T/sub c/ = 10K)LuRuB/sub 2/.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6787885
• 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
CRITICAL FIELD
CRYSTAL STRUCTURE
DATA
DEBYE TEMPERATURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ERBIUM BORIDES
ERBIUM COMPOUNDS
EXPERIMENTAL DATA
INFORMATION
LUTETIUM BORIDES
LUTETIUM COMPOUNDS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
NUMERICAL DATA
ORDER PARAMETERS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
RHODIUM BORIDES
RHODIUM COMPOUNDS
RUTHENIUM BORIDES
RUTHENIUM COMPOUNDS
SPECIFIC HEAT
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM BORIDES
YTTRIUM COMPOUNDS