Crystal field and magnetocrystalline anisotropy in ErNiAl

We present a study of the crystal field and electronic structure in an ErNiAl intermetallic compound based on the inelastic neutron spectroscopy, magnetic susceptibility, specific heat data, and first-principles density-functional calculations. We have fully determined the lower half of the ground-state multiplet energy-level scheme in ErNiAl. Several possible sets of the crystal-field parameters have been found to describe all our experimental data. Magnetic-susceptibility data revealed a rather weak magnetocrystalline anisotropy.