Untitled

Low-frequency internal friction study of phase transitions in La1/3Sr2/3FeO3−δ ceramics

“…LaFeO 3 -based compounds are known to be ferroelastic [21,22], and deformation domains can be formed in these materials on transformation from high symmetry phase to low symmetry phase during cooling. Such deformation domains in LaCoO 3 -based ferroic perovskites have been widely reported [23,24]. Considering the motion of ferroelectric domain walls in ferroelectric ceramics could result in the relaxation internal friction peak [25][26][27], thus we believe that P oxygen /P air peaks in La 1/3 Sr 2/3 FeO 3−δ ceramics should be originated from the motion of ferroelastic domain walls induced by stress.…”

Mechanical properties of LaFeO3 ceramics

“…A similar domain structure is also observed in other rhombohedral perovskites. 37,38 The maximum number of twin boundaries observed by TEM in orthorhombic LaFeO 3 grains was three. About 50% of the investigated LaFeO 3 grains contained twin domains, the number increasing slightly after application of a mechanical stress of 500 MPa.…”

Time and frequency dependent mechanical properties of LaCoO3-based perovskites: Neutron diffraction and domain mobility

“…10 The availability and mobility of defects in ferroelastic perovskites and the mechanisms explaining their appearances have been studied by numerous techniques. [4][5][6][7] The direct visual characterization and the studies of the mobility of twins, stacking faults, dislocations, and other related defects in LaCoO 3 based perovskites both at room and at high temperatures were studied by high resolution TEM 2,[11][12][13] and under applied compressive stresses by SEM, 14,15 where domains and their movements were directly visualized, in many cases even during in situ experiments. Another set of straightforward and revealing techniques used to study domain mobility and reorientation under applied compressive stress in LaCoO 3 based perovskites, very often presented as domain switching, was in situ X-ray or neutron diffraction techniques.…”