Dependence of the effective masses in YbAl3 on magnetic field and disorder.
The susceptibility and specific heat--and hence the effective mass--of the intermediate valence compound YbAl3 show anomalous enhancement below the Fermi liquid temperature T(coh) approximately 40 K. We show that these anomalies are suppressed by alloying in Yb1-xLuxAl3 indicating high sensitivity to lattice coherence. The de Haas-van Alphen effective masses for key branches of the Fermi surface are reduced by magnetic fields B>40 T. We argue that this reduction does not arise from 4f polarization but reflects renormalization of the quasiparticle states by the field.
Shizuoka University, Shizuoka 422-8529, Japan.
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T
Ebihara
E D
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Bauer
A L
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Cornelius
J M
JM
Lawrence
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N
Harrison
J D
JD
Thompson
J L
JL
Sarrao
M F
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Hundley
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Uji