Twin structure in Yb:YAl3(BO3)4 crystal

Abstract

Twin structure is a defect in the self-frequency-doubling laser crystal material Yb:YA13(BO3)4 (YbYAB). Based on atomic force microscopy (AFM) observations, a check-like twin structure in YbYAB crystals is found. This kind of twin structure has three twin composition planes: (10̄1), (0̄11) and (̄101). These three twin composition planes result in a series of twin boundaries in two directions, forming a check-like pattern on each face. From the orientation of the chemical etching pits on each side of the twin boundary, it is found that the twin element is 'twin plane ⊥ y axis', alternatively indicated as 'twin plane {1120}'. The two single crystals composing the twin are a right form and a left form. This kind of twin is similar to the Brazil twin found in quartz. © 2001 International Union of Crystallography.