Magnetism, spin fluctuations, and non-Fermi-liquid behavior in (U{sub x}La{sub 1-x}){sub 2}Zn{sub 17}

Journal Article · Wed Aug 01 00:00:00 EDT 2001 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.64.064413· OSTI ID:40277343

von Blanckenhagen, G -F; Scheidt, E -W; Schreiner, T; Stewart, G R

We present results of the low-temperature specific heat C of samples of the series (U{sub x}La{sub 1-x}){sub 2}Zn{sub 17}, combined with measurements of the low-temperature magnetic susceptibility ({chi}) and resistivity ({rho}). For x>0.8 we find antiferromagnetic order in coexistence with heavy-fermion behavior. An extrapolation of T{sub N} as a function of the uranium concentration implies that T{sub N} vanishes for x=0.8; at x=0.8, no magnetic order is detected experimentally at temperatures above 0.06 K. The non-Fermi-liquid (NFL) behavior predicted at such a point in the magnetic phase diagram may be observed, but not as clearly as in other systems; some of the behavior is more consistent with spin fluctuations. As the uranium concentration is lowered below x=0.8, C continues to rise in the low-temperature limit, while {chi}{proportional_to}{chi}{sub 0}-aT{sup 0.5}, but C seems to tend towards the behavior of a Fermi liquid with spin fluctuations at the lowest temperatures (T<0.25 K). First at x=0.3 the temperature dependence of C/T is found to be contrary to Fermi-liquid behavior, while {chi}{proportional_to}{chi}{sub 0}-a log T. Thus non-Fermi-liquid behavior is not found so unambiguously at the concentration where T{sub N} vanishes as expected by a quantum critical point theory, but rather at lower uranium concentrations. This presents the possibility that NFL behavior in (U{sub x}La{sub 1-x}){sub 2}Zn{sub 17} is not due to nearness to a quantum critical point, but rather to disorder or the presence of spin fluctuations.

• Sponsoring Organization: (US)
• DOE Contract Number: FG05-86ER45268
• OSTI ID: 40277343
• Journal Information: Physical Review B, Vol. 64, Issue 6; Other Information: DOI: 10.1103/PhysRevB.64.064413; Othernumber: PRBMDO000064000006064413000001; 009130PRB; PBD: 1 Aug 2001; ISSN 0163-1829
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EXTRAPOLATION
FERMI GAS
FLUCTUATIONS
MAGNETIC SUSCEPTIBILITY
MAGNETISM
PHASE DIAGRAMS
SPECIFIC HEAT
SPIN
TEMPERATURE DEPENDENCE
URANIUM