Datensatz

Zusammenfassung

We present measurements of the magnetization M, specific heat C, resistivity., and magnetoresistance MR of single-crystalline hexagonal CeAuSn for temperature down to T = 1.6 K and in magnetic field up to B = 12 T. Antiferromagnetic ordering at T-N = 4.4 K is observed as previously found for polycrystalline samples. A strong magnetic easy-plane anisotropy of M for B perpendicular and parallel to the c direction is found with M-perpendicular to/M-parallel to approximate to 15 in B = 0.1 T around T-N, which is attributed to crystal-electric-field anisotropy. The analysis of the magnetic susceptibility indicates ferromagnetic correlations above T-N. Measurements of M(T) under hydrostatic pressure P show that T-N(P) increases linearly with P at a small rate of 0.035 K/kbar up to 4 kbar and gradually saturates approaching P = 16 kbar. Zero-field Delta C/T, the phonon contribution to C being subtracted, is proportional to T-2 below T-N indicating a gapless spin-wave spectrum. It is found that all Delta C(T,B)/T curves for B = 0-9 T cross at the same temperature, providing an example of a particularly well defined isosbestic point in a very narrow region around T-iso = 6.6 K. Finally, rho(T) and MR experiments with current perpendicular and parallel to B allow us to separate orbital effects from the Zeeman splitting.