Structure, magnetic, and electrical properties of bismuth niobates doped with d-elements: XII. Magnetic behavior of Bi3Nb1-x Mn (x) O7-delta solid solutions

摘要

Magnetic behavior of Bi3Nb1-x Mn (x) O7-delta solid solutions of cubic and tetragonal modifications has been examined in comparison. The magnetic susceptibility studies have revealed that paramagnetic manganese atoms in the solid solutions of cubic and tetragonal modification exist as Mn(III) and Mn(IV) monomers as well as exchange-bound dimers: Mn(III)OMn(III), Mn(IV)OMn(IV), and Mn(III)OMn(IV). The exchange parameters and the distribution of monomers and dimers in the solid solutions have been determined as function of the paramagnetic atoms fraction.