Field-Temperature Phase Diagram and Entropy Landscape of CeAuSb$_2$

Authors :: Zhao, Lishan
Yelland, Edward A.
Bruin, Jan A. N.
Sheikin, Ilya
Canfield, Paul C.
Fritsch, Veronika
Sakai, Hideaki
Mackenzie, Andrew P.
Hicks, Clifford W.
Source :: Phys. Rev. B 93, 195124 (2016)
Publication Year :: 2016
Abstract: We report a field-temperature phase diagram and an entropy map for the heavy fermion compound CeAuSb$_2$. CeAuSb$_2$ orders antiferromagnetically below $T_N=6.6$~K, and has two metamagnetic transitions, at 2.8 and 5.6~T. The locations of the critical endpoints of the metamagnetic transitions, which may play a strong role in the putative quantum criticality of CeAuSb$_2$ and related compounds, are identified. The entropy map reveals an apparent entropy balance with Fermi liquid behavior, implying that above the N\'{e}el transition the Ce moments are incorporated into the Fermi liquid. High-field data showing that the magnetic behavior is remarkably anisotropic are also reported.<br />Comment: 7 pages, 9 figures