Abstract
Single crystals of LiEr and LiHo have been grown and their magnetic properties measured from 1.3 K to 300 K. LiHo turned out to be a nearly ideal Ising ferromagnet with K and a saturation magnetization along the crystalline axis of . In LiEr no ordering was observed, but extrapolation indicates that below 0.5 K it will be ferromagnetic with the magnetic moments in the crytalline plane. From the susceptibilities the crystal-field parameters with have been extracted giving for in LiEr: 430., -985., 1185., -5., . () and for in LiHo: 470., -825., 1050., -10., (). The exchange constants were found to be small compared to the dipole interactions. Furthermore the NMR spectra have been obtained in these materials as well as in LiTb thereby determining the second-order crystal-field parameters at the Li site: for the Er, Ho, and Tb compound, respectively. The crystal-field parameters are compared to values calculated from point charges, showing agreement at the Li sites but not at the rare earth sites.
- Received 23 June 1975
DOI:https://doi.org/10.1103/PhysRevB.12.5315
©1975 American Physical Society