Domain structure in (La, Pr)GaO3 solid solutions

Substitution of La by Pr in La1-xPrxGaO3 solid solutions crystals leads to a decrease of spontaneous strains. There exist six possible twin states of the m3mFmmm species in the orthorhombic phase. The distorted perovskite unit cell becomes pseudotetragonal at composition xapproximate to0.51 what leads to degeneracy to three twin states (the m3mF4/mmm species). The {110} and {112} reflection twins and axial twins with compositional planes close to {211} (S-walls) were identified in crystals with x=0.05, 0.10, 0.30. All observed twins are characteristic for crystals of GdFeO3 type perovskite-like structure. It was shown that orientations of S-walls do not depend on La/Pr ratio in the ranges of xless than or equal to0.3 and strongly vary in the composition range 0.3More