Interplay between superconductivity and itinerant ferromagnetism in Y/sub 9/Co/sub 7/ at high pressure

Technical Report · Sat Jan 01 00:00:00 EST 1983

DOI:https://doi.org/10.2172/5783052· OSTI ID:5783052

Huang, C Y; Wolf, S A; Olsen, C E; Fuller, W W; Huang, J H; Ting, C S

The theory of the interplay between superconductivity and itinerant ferromagnetism based on the single conduction band model in the mean field approximation is summarized. This theory predicts that superconductivity and itinerant ferromagnetism cannot co-exist, that the higher temperature magnetic phase can transform into the low temperature superconducting state, and that a superconducting state will not transform into a ferromagnetic state at a temperature below the superconducting transition. For the magnetic superconductor Y/sub 9/Co/sub 7/ we have reviewed the experimental results and in particular, we have shown that pressure suppresses magnetism resulting in a higher superconducting transition temperature and have concluded that Y/sub 9/Co/sub 7/ is an itinerant magnet. Pressure also sharpens the superconducting transition and increases the upper critical field, signifying that the ferromagnetic correlations and superconducting fluctuations co-exist but very spatially. For pressures greater than 6 kbar, the magnetoresistance is always positive, further indicating the suppression of magnetism by high pressure. Several microscopic experiments and some improvement in theory are suggested.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Naval Research Lab. (NRL), Washington, DC (United States); Houston Univ., TX (USA). Dept. of Physics
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5783052
• Report Number(s): LA-UR-83-2830; CONF-830763-16; ON: DE84001034
• Resource Relation: Conference: 9. AIRAPT conference, Albany, NY, USA, 25 Jul 1983
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COBALT ALLOYS
FERROMAGNETISM
SUPERCONDUCTIVITY
YTTRIUM ALLOYS
BAND THEORY
CRITICAL FIELD
ELECTRIC CONDUCTIVITY
EXPERIMENTAL DATA
FLUCTUATIONS
HIGH PRESSURE
INTERMETALLIC COMPOUNDS
PRESSURE DEPENDENCE
THEORETICAL DATA
TRANSITION TEMPERATURE
ALLOYS
DATA
ELECTRICAL PROPERTIES
INFORMATION
MAGNETIC FIELDS
MAGNETISM
NUMERICAL DATA
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
VARIATIONS
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