Synthesis, structural characterization and magnetic properties of CoInOPO4 with the α-Fe2OPO4 structure
Résumé
Understanding the structure and magnetic properties of materials is very interesting since they have been implemented in a wide variety of cutting-edge technologies, such as magnetic storage, memory technology and magnetic resonance imaging phosphate. The CoInOPO4, was synthesized using the sol-gel method and its crystal structure was established from powder X-ray diffraction data using Rietveld method. This phosphate was additionally examined by scanning electron microscopy (SEM), infrared and Raman spectroscopy to provide supplementary structural information. CoInOPO4 is isotypic with the mixed-valence compound α-Fe2OPO4, which crystallizes in the orthorhombic symmetry with the space group Pnma. The structure of this phosphate consists in a three-dimensional network built up from (Co(2)/In(2))O6 octahedra, (In(1)/Co(1))O5 square pyramid, and PO4 tetrahedra. Infrared and Raman phonons analysis were provided and the temperature dependence Raman spectroscopy strongly suggests a high-temperature structural instability (around 600°C). The magnetic investigation revealed a Curie-Weiss temperature of this phosphate equal to −47.79 K, indicating that the dominating interactions are antiferromagnetic.