The effect of pressure on the heavy-electron superconductors UBe sub 13 and URu sub 2 Si sub 2

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5216109

McElfresh, M W

A study of the pressure dependence of the normal-state properties of the heavy-electron superconductors UBe{sub 13} and URu{sub 2}Si{sub 2} was undertaken in order to explore the relationship of Kondo lattice properties to the properties expected for dilute Kondo systems. The compounds UBe{sub 13} was the second heavy-electron superconductor identified, having a superconducting transition temperature 0.97 K and an electronic specific heat coefficient of 1100 mJ/mole-K{sup 2}. The electrical resistivity {rho}(T) was measured at pressures to 152 kbar showing two rates of increase in the temperature of the {rho} maximum T, one rate of 0.25 K/kbar below {approximately} 30 kbar and a second rate of 0.65 K/kbar above {approximately} 30 kbar. At low temperatures {rho}(T) increases quadratically with temperature T, with the T range increasing from less than 1 K at 1 bar to over 16.5 K at 150 kbar. The compound URu{sub 2}Si{sub 2} exhibits two electronic phase transitions: superconductivity at T{sub c} 1.5 K and an itinerant antiferromagnetic transition at T{sub o} 17.5 K. From pressure-dependent resistivity {rho}(T) measurements to 15.4 kbar the effect of pressure was shown to decrease T{sub c} at a rate of {minus}95 mK/kbar and increase T{sub o} at a rate of 130 mK/kbar below 12 kbar and at a higher rate at pressures.

• Research Organization: California Univ., San Diego, CA (USA)
• OSTI ID: 5216109
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ACTINIDE ALLOYS
ALLOYS
ANTIFERROMAGNETISM
BERYLLIUM ALLOYS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MAGNETISM
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
PRESSURE DEPENDENCE
RUTHENIUM ALLOYS
SILICON ALLOYS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
URANIUM ALLOYS