Domain structure of YBa2Cu3O7-x single crystals

The twinning in the orthorhombic YBa2Cu3O7phase creates domains related each other by mirror symmetry and/or a slight rotation by about 1°. Rows of twin tips and sets of mlcrotwins produce lattice rotations for accommodation of the slight misorientation between neighbouring domains. We show the higher misorientation about 1° tends to be accommodated by set of microtwins. The rows of tapered twin tips cause the smaller lattice rotation. In this way the “single crystals” are composed of twinned mutually disoriented regions.