Anomalies of phase diagrams and physical properties of antiferrodistortive perovskite oxides

摘要: Abstract The influence of rotomagnetic (RM), rotoelectric (RE) and magnetoelectric (ME) coupling on phase diagram properties antiferrodistortive (AFD) perovskite oxides was reviewed. main examples we consider in the review are typical AFD perovskites, such as incipient ferroelectrics EuTiO3, SrTiO3, EuxSr1-xTiO3, multiferroic BiFeO3 Bi1-xRxFeO3 (x = La, Nd). strong RM, RE ME couplings physical diagrams including antiferromagnetic (AFM), ferroelectric (FE) structural phases has been revealed framework Landau-Ginzburg-Devonshire (LGD) theory, well prediction novel (double triple) demonstrated. In especially focused (a) possibility to induce FM EuTiO3 (as other paraelectric AFM oxides) by application an electric (magnetic) field due coupling; (b) analysis size effects EuxSr1-xTiO3 nanosystems, where LGD theory predicts presence triple AFD-FE-FM(AFM) at low temperatures; (c) appearance improper spontaneous polarization pyroelectricity vicinity antiphase domain boundaries, twin walls, surfaces interphases non-ferroelectric SrTiO3 induced flexoelectricity rotostriction; (d) occurrence symmetry monoclinic with in-plane FE thin strained films its stabilization over wide temperature range oxygen octahedra tilts flexoelectric rotostriction (e) discussion a surprisingly size-induced increase transition caused joint action RM elastic stress accumulated intergrain spaces dense ceramics. Noteworthy, results obtained within approach show controlling multiferroicity, FE, bulk nanosized ferroics, help and/or electric/magnetic application. Since theoretical qualitative agreement experimental results, conclude that can be successfully applied many oxides.