Site-specific doping, tunable dielectric properties and intrinsic paramagnetism in Mn-doped SrTiO 3

Abstract

Mn doping in SrTiO3 leads to the emergence of qualitatively distinct and novel physical properties. We show that Mn ions can be controllably doped at either of the perovskite A (Sr) or B (Ti) site as well as at both sites simultaneously and the resultant physical properties depend intimately on the particular dopant site. We critically review the recent literature on various Mn-doped SrTiO3 systems, which includes reports of dielectric glass, spin-glass and ferromagnetism and by combining experiments with first-principles calculations, we demonstrate that depending on the particular dopant site for Mn ions, the dielectric properties can be widely tuned from a quantum paraelectric to a dielectric glass. However, the intrinsic magnetism in all these cases remains essentially paramagnetic for phase-pure systems.