Experimental evidences of the shape-induced structural distortion of SrTiO<inf>3</inf>single crystals from impurity Mn⁴⁺ions electron paramagnetic resonance

Abstract

© Kazan Federal University (KFU). A study of high-quality SrTiO3single crystals doped with the Mn4+ions in the cubic phase (T > 105 K) with X-band electron paramagnetic resonance reveals direct correspondence between a shape of a sample and magnetic anisotropy of the impurity Mn4+centers. In particular, for a sample with the shape of a square base rectangular prism, a size of (a × a × h) and faces perpendicular to the 〈100〉 crystallographic directions, zero-field splitting parameter D is approximately proportional to (a/h = 1) quantity. Temperature dependence of D indicates that this peculiar symmetry lowering is a feature characteristic for the cubic Fm3m phase of the strontium titanate. Diminishing of the D value with the decrease of the surface roughness for a thin (001)-oriented SrTiO3:Mn platelet shows that the observed effect originates from the sample surface.