Effects of hydrogen doping on UPd[sub 2]Al[sub 3]

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.9948· OSTI ID:6986832

Kim, W W; Stewart, G R ^[1]

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1. Department of Physics, University of Florida, Gainesville, Florida 32611-2085 (United States)

We have succeeded in doping hydrogen into the semiheavy'' UPd[sub 2]Al[sub 3] up to a stable concentration of UPd[sub 2]Al[sub 3]H[sub 1.3]. Magnetism is depressed in UPd[sub 2]Al[sub 3]H[sub [ital x]]: [ital T][sub [ital N]] falls from 14.5 K with an initial slope of about 55 mK/%H, [chi](1.8 K) initially remains relatively constant but rises substantially for [ital x][gt]0.34 to 21.4 memu/mole at [ital x]=1.30, while the effective moment inferred from the Curie-Weiss behavior in the susceptibility above 100 K falls monotonically with hydrogen doping from 3.39[mu][sub [ital B]] for [ital x]=0 to 2.82[mu][sub [ital B]] for [ital x]=1.30. Superconductivity is totally suppressed by approximately [ital x]=0.5. At the same time as the antiferromagnetic peak in the specific heat is being depressed to lower temperatures with increasing [ital x], the specific heat divided by temperature data show more and more of an upturn below 10 K, reminiscent of the behavior seen in heavy fermion systems like CeCu[sub 2]Si[sub 2]. Whether or not this upturn in [ital C]/[ital T] is magnetic in character was checked via measurements of the magnetization at 1.8 K, which showed no signs of saturation up to 5.5 T, and of the field dependence of the low-temperature (0.3 K[le][ital T][lt]1.5 K) specific heat in 14 T, which showed approximately a 25% decrease. Such a decrease in the specific heat with field is significantly smaller than that seen in, e.g., CeCu[sub 6] (65% suppression in 14.5 T) where magnetic correlations are thought to be strong, and is similar to the size effect seen in nonsuperconducting samples of CeCu[sub 2]Si[sub 2] (35% suppression in 10 T). However, whether this upturn in [ital C]/[ital T] in UPd[sub 2]Al[sub 3]H[sub 1.3] is indicative of an electron effective mass increased by a factor of 4 vs pure UPd[sub 2]Al[sub 3], or due to magnetic correlations/short-range magnetic order remains an open question.

• DOE Contract Number: FG05-86ER45268
• OSTI ID: 6986832
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:14; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ACTINIDE COMPOUNDS
ALLOYS
ALUMINIUM COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HYDROGEN ADDITIONS
INTERMETALLIC COMPOUNDS
MAGNETIC PROPERTIES
PALLADIUM COMPOUNDS
PHYSICAL PROPERTIES
SPECIFIC HEAT
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
URANIUM COMPOUNDS