SrTiO3—Glimpses of an Inexhaustible Source of Novel Solid State Phenomena

Wolfgang Kleemann,Paula M Vilarinho,Jan Dec,Alexander Tkach

doi:10.3390/condmat5040058

Abstract

The purpose of this selective review is primarily to demonstrate the large versatility of the insulating quantum paraelectric perovskite SrTiO3 explained in “Introduction” part, and “Routes of SrTiO3 toward ferroelectricity and other collective states” part. Apart from ferroelectricity under various boundary conditions, it exhibits regular electronic and superconductivity via doping or external fields and is capable of displaying diverse coupled states. “Magnetoelectric multiglass (Sr,Mn)TiO3” part, deals with mesoscopic physics of the solid solution SrTiO3:Mn2+. It is at the origin of both polar and spin cluster glass forming and is altogether a novel multiferroic system. Independent transitions at different glass temperatures, power law dynamic criticality, divergent third-order susceptibilities, and higher order magneto-electric interactions are convincing fingerprints.

Highlights

In this review, we focus onto two research lines of strontium titanate, SrTiO3 (STO):(1) the low-temperature phases around the quantum critical point of pure STO, and (2)the disordered electric and magnetic dipolar glassy phases in the solid solution STO: Mn
We focus onto two research lines of strontium titanate, SrTiO3 (STO): (1) the low-temperature phases around the quantum critical point of pure STO, and (2)
In view of recently ascertained magnetic superspin glasses (SSG) of dipolarly coupled magnetic nanoparticles at low concentration [22], a related electric superdipolar glass (SDG) has become envisaged. It should behave like a relaxor ferroelectric [23] in terms of a superglassy critical power law behavior of the ε (f) vs. T peak position Tm

Summary

Introduction

We focus onto two research lines of strontium titanate, SrTiO3 (STO):. (1) the low-temperature phases around the quantum critical point of pure STO, and (2). Quantum corrections to the temperature were proposed to describe the critical behavior of STO from the beginning [1]. In order to account for the obvious deviations from the mean-field Curie–Weiss behavior, some of us proposed a generalized modified “quantum Curie–Weiss law” [3]. Quantum corrections to the temperature proposed to describe the critical behavior of being related to the ground state energy of the quantum oscillator, E. Obtained on pure STO from a conventional power-law fit for 4 ≤ T ≤ 50 K [4], where saturation effects where C stands for the Curie constant, γ for the critical exponent, and T = T coth(T ⁄T ) for the deviated below ≈ 4 K.

Routes ofbest

The Magnetoelectric

Conclusions