Mössbauer Effect, Ionic Conductivity, and Ionic Thermoconductivity Studies of Ionic Spin Fluctuations in the Magnetically Ordered Fe3+: NiTiO3 System

Abstract

Mössbauer measurements are carried out in the NiTiO3‐25 mol% Fe2O3 system when the system is prepared by annealing at different annealing temperatures. Anomalous Mössbauer spectra are observed in the 1280 °C‐annealed sample indicating the presence of an ionic spin fluctuation effect which disappears when the annealing temperature of the solid solution is increased. In the 1450 °Cannealed system only normal Mössbauer spectra without any anomalous central enhancement are observed. This result can be understood by assuming an inhomogeneous diffusion of the Fe3+ ions in the 1280 °C‐annealed sample and their uniform distribution in the 1450 °C‐annealed sample. Ionic conductivity and ionic thermoconductivity measurements, carried out in NiTiO3‐, Fe2O3‐, and NiTiO3‐25 mol% Fe2O3 systems, support this assumption.