Magnetic Properties of Neodymium Compounds with Va Elements

Magnetic properties of NdP, NdAs and NdSb have been investigated over the temperature range from 4°K to 300°K. The ratio of the susceptibility at the Néel temperature to the one extraporated to 0°K is much larger than 3/2, suggesting that these compounds have large crystal anisotropy. Metamagnetic behaviors were observed at 4.2°K, and the product of the critical field and the susceptibility at the Néel temperature was found to be nearly constant at 7 kOe e.m.u. per mole for all of the compounds. This result can be explained by a simple sublattice model. The value of the saturation magnetization and the large anisotropy are discussed in terms of the admixing of the excited state \(₈\) to the ground state \(₆\) of Nd 3+ in a cubic crystal field.