Structural, magnetic, and optical properties of A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni)

Authors

Spencer H. Porter, University of WollongongFollow
Jie Xiong, Ohio State University
Maxim Avdeev, ANSTOFollow
David Merz, University of WollongongFollow
Patrick M. Woodward, Ohio State UniversityFollow
Zhenguo Huang, University of WollongongFollow

RIS ID

108314

Publication Details

Porter, S. H., Xiong, J., Avdeev, M., Merz, D., Woodward, P. M. & Huang, Z. (2016). Structural, magnetic, and optical properties of A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni). Inorganic Chemistry, 55 (12), 5772-5779.

Abstract

Combined synchrotron and neutron powder diffraction indicates that A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni) compounds crystallize with triclinic P1 symmetry. Lattice parameters expand as expected with successive increases in the ionic radius of the A2+ ion. Cation disorder on the octahedral sites increases as the ionic radii of A2+ ion decreases. Direct-current magnetic susceptibility measurements indicate that all compounds with magnetic A2+ ions order anti-ferromagnetically with transition temperatures ranging from 12 to 15 K. Effective magnetic moments for A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni) are 5.16, 11.04, 10.08, 9.76, and 7.96 μB per formula unit, respectively, in line with calculated values for high-spin transition metal ions. With the exception of Co3V4(PO4)6 the ultraviolet-visible spectra are dominated by d-d transitions of the V3+ ions. The striking emerald green color of Co3V4(PO4)6 arises from the combined effects of d-d transitions involving both V3+ and Co2+.