Magnetic properties of the heavy-fermion system UBe sub 13

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5215442

Ma, Y P

UBe{sub 13} is one of the heavy-fermion superconductors with an unusually large electronic specific heat and an unconventional magnetic susceptibility. Magnetization in both the normal and mixed states of UBe{sub 13} was measured in magnetic fields up to 19 Tesla and temperatures down to 50 mK. For high fields and low temperatures, two types of capacitive DC magnetometers, a cantilever (CMAG) and a diaphragm (DMAG) magnetometer, were developed. These are at present the only DC magnetometers that work simultaneously in a dilution refrigerator and a resistive Bitter magnet. In the normal state the magnetization at temperatures above T{sub c} shows a slight deviation from simple linear behavior. Below T{sub c}, however, the magnetization shows an unusual upturn at fields greater than 14T, which may be explained by field induced spin fluctuation or SDW transition. In the mixed state of UBe{sub 13}, a large and time-dependent hysteresis in the magnetization curve was observed. This time dependence is well described by an exponential decay, and the relaxation time is strongly dependent on temperature and magnetic field. Two different temporal responses corresponding to regimes above and below a crossover point in the hysteresis loops are found.

• Research Organization: Boston Univ., MA (USA)
• OSTI ID: 5215442
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
420201 -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTINIDE ALLOYS
ALLOYS
BERYLLIUM ALLOYS
ELECTRONIC EQUIPMENT
EQUIPMENT
FERMIONS
FLUXMETERS
INTERMETALLIC COMPOUNDS
MAGNETIC PROPERTIES
MAGNETOMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
PHYSICAL PROPERTIES
SQUID DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TIME DEPENDENCE
TRANSITION TEMPERATURE
URANIUM ALLOYS