Polarization of domain boundaries in SrTiO3 studied by layer group and order-parameter symmetry


Based on a recently developed combination of layer group analysis with order-parameter symmetry, we study the polarity of antiphase domain boundaries (APBs) and ferroelastic twin boundaries (TBs) in SrTiO3. In addition to the celebrated layer group analysis of domain twins, the present method allows us to investigate tensor properties of domain walls also for the case where order-parameter variables other than the spontaneous ones are active.

Microscopic symmetry and polarization of two different ferroelastic twins
Representation of two different ferroelastic twins with normal n=[110] at position p=(0,0,0) in tetragonal SrTiO3, together with the symmetry elements of the corresponding layer groups. (a) Pure orientational twin (11|21). The corresponding twin wall is an easy (HT) wall. The twin in (b) is of mixed type, i.e., (11|22), where the corresponding twin wall is a hard (HH) one. The arrows at the centers show polarization predicted by the theory.  

Contact person: Ivan Rychetský
Collaborating institutions: University of Vienna, Faculty of Physics, Wien, Austria.