Local structure and magnetism of L ax e u1-x P O4 solid solutions

Abstract

By combining high spinning speed (60 kHz) and low-field (4.7 T) P31 solid-state NMR with magnetic susceptibility measurements, we experimentally characterized a series of solid solutions belonging to the LaxEu1-xPO4 (0≤x≤1) series. Analyses of the magnetic susceptibility data were carried out using the free ion model and crystal field theory calculations allowing to extract the electronic structure. The paramagnetic shifts of the P sites having one Eu3+ cation in their surrounding were predicted by combining the determined crystal field and energy level values with density functional theory (DFT) calculations. For the La0.9Eu0.1PO4 sample, these theoretical shifts gave a very good overall trend allowing the unambiguous attribution of each P site. This study paves the way for the future analysis of both magnetic susceptibility and NMR data for a broad range of materials containing paramagnetic rare-earth cations.