Magnetic interactions and oxidation state determination of Mn(2-x)V(1+x)O4 (x = 0, 1/3 and 1) magnetoresistive spinel family

J. M. DE PAOLI

JOURNAL OF SOLID STATE CHEMISTRY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: San Diego; Año: 2013 vol. 205 p. 57 - 57

0022-4596

xidation states of transition metal cations in spinels-type oxides are sometimes extremely difficult to determine by conventional spectroscopic methods. One of the most complex cases occurs when there are different cations, each one with several possible oxidation states, as in the case of the magnetoresistent Mn(2-x)V(1+x)O4 (x = 0, 1/3 and 1) spinel-type family. In this contribution we describe the determination of the oxidation state of manganese and vanadium in Mn(2-x)V(1+x)O4 (x = 0, 1/3,1) spinel-type compounds by analyzing XANES and high-resolution Kb X-ray fluorescence spectra. The ionic models found are Mn2+2V4+O4, Mn2+5/3V3.5+4/3O4 and Mn2+V3+2O4. Combination of the present results with previous data provided a reliable cation distribution model. For these spinels, single magnetic electron paramagnetic resonance (EPR) lines are observed at 480 K showing the interaction among the different magnetic ions. The analysis of the EPR parameters show that g-values and relative inten