Magnetic orderings in BaTi1−xFexO3-δ (with x = 0.1)

We report here various magnetic orderings and Para magnetism in Iron (both56Fe and enriched 57Fe) doped BaTi1−xFexO3-δ (x = 0.1) pristine and Nano-crystalline systems. We tried to establish that oxygen vacancies in different charge states are the key factors for the magnetic behavior of these systems. The samples were prepared by the solid state reaction method and were formed predominantly in tetragonal phase with a trace amount of hexagonal phase. The nascent sizes of the grains were in the micron order. The grains of the pristine sample were refined by mechanical milling. The presence of oxygen vacancies in different charge states and their relative intensities in the pristine and milled samples were investigated by the Photoluminescence Spectroscopic technique in the visible range. Coexistence of ferromagnetic and antiferromagnetic orderings among Fe3+ ions mediated via oxygen vacancies in different charge states was observed through clear sextet patterns in the Mössbauer spectra which was corroborated by SQUID measurements. Whereas increase in oxygen vacancies increased the overall magnetization in these materials, the decrease in grain sizes made the material softer and eventually resulted in single domain formation.