The dynamics of transformation twins in SrxBa1−xSnO3 (x = 0.6, 0.8) perovskite was studied by dynamical mechanical analysis in 3-point bending. The material underwent phase transitions from orthorhombic to tetragonal and cubic structures upon heating. The mechanical loss signatures of the transformation twins included relaxation and frequency-independent peaks in the orthorhombic and tetragonal phases, with no observed energy dissipation in the cubic phase. The macroscopic shape, orientation and relative displacements of twin walls were deduced from the bending and anisotropy energies. The mechanical loss angle and distribution of relaxation time were explained in terms of the bending modes of domain walls.

Effect of Internal Friction on Transformation Twin Dynamics in Perovskite SrxBa1−xSnO3 (x = 0.6, 0.8). M.Daraktchiev, E.K.H.Salje, W.T.Lee, S.A.T.Redfern: Physical Review B, 2007, 75[13], 134102 (7pp)