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Specific Heat Study of Non-Fermi Liquid Behavior in CeNi_2Ge_2: Anomalous Peak in Quasi-Particle Density-of-States

Yuji Aoki·Jun Urakawa·Hitoshi Sugawara·Hideyuki Sato·Tadashi Fukuhara·Kunihiko Maezawa
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Abstract

To investigate the non-Fermi liquid (NFL) behavior in a nonalloyed system CeNi_2Ge_2, we have measured the temperature and field dependences of the specific heat C on a CeNi_2Ge_2 single crystal. The distinctive temperature dependence of C/T (~a-b*T^(1/2)) is destroyed in almost the same manner for both field directions of B//c-axis and B//a-axis. The overall behavior of C(T,B) and the low-temperature upturn in magnetic susceptibility can be reproduced, assuming an anomalous peak of the quasi-particle-band density-of-states (DOS) at the Fermi energy possessing (epsilon)^(1/2) energy dependence. Absence of residual entropy around T=0 K in B~0 T has been confirmed by the magnetocaloric effect measurements, which are consistent with the present model. The present model can also be applied to the NFL behavior in CeCu_{5.9}Au_{0.1} using a ln(epsilon)-dependent peak in the DOS. Possible origins of the peak in the DOS are discussed.

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Yuji Aoki, Jun Urakawa, Hitoshi Sugawara, Hideyuki Sato, Tadashi Fukuhara, Kunihiko Maezawa. 1997-09-20. Specific Heat Study of Non-Fermi Liquid Behavior in CeNi_2Ge_2: Anomalous Peak in Quasi-Particle Density-of-States. https://doi.org/10.1143/jpsj.66.2993

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