Magnetic and ferroelectric properties of Fe doped SrTiO3-δ films

Recent interest in SrTiO3 stems from its wide applicability in microwave devices based on the tunable characteristics of dielectric constant in the microwave frequency range. It is obvious that for any such application, SrTiO3 should have a ferroelectric Curie temperature (TC) close to room temperature or higher. By inducing strains by chemical substitutions, it was possible to obtain TC as high as 2000C in SrTiO3 modified with Fe4+. Hysteresis loops obtained confirms the presence of ferroelectric domains. Two apparent transitions, one at ∼200 0C and another ∼300 0C were seen in ε', which are replicated as sharp drops in resistivity curves. These temperatures far exceed the TCs reported in the literature till now and could open new avenues for innumerable other applications for SrTiO3. The magnetic properties of Fe doped SrTiO3 are also investigated. Low doping of Fe exhibits simple antiferromagnetic behaviour.