The Magnetic Susceptibilities of Lanthanum, Cerium, Praseodymium, Neodymium and Samarium, from 1.5 K to 300 K

Abstract

The magnetic susceptibilities of the rare-earth metals lanthanum, cerium, praseodymium, neodymium and samarium have been measured over the temperature range 1.5°K to 300°K. Low temperature anomalies correlating with recent specific heat measurements have been found in cerium, neodymium and samarium at temperatures of 12.5°K, 7.5°K and 14.8°K respectively, and it is believed that these metals become anti-ferromagnetic below these temperatures. At higher temperatures the susceptibilities of cerium and praseodymium obey the Curie-Weiss law, with effective atomic moments of 2.51 and 3 56 Bohr magnetons respectively. Neodymium obeys a law of the form χ = C/(T − θ) + K, where the Curie constant C indicates an effective atomic moment of 3.3 Bohr magnetons (μ_B). These moments are in fair agreement with the values expected for the trivalent ions of the elements, assuming Russell-Saunders coupling of the orbital and spin moments of the 4f electrons.