Etching figures in neodymium gallate and yttrium aluminate crystals

The dislocations existing in single crystals of neodymium gallate and yttri um aluminate grown by the Czochralski technique have been studied by means of etch pits. The data concerning their solubility in cases of different di rections of a face orientation, various treatment temperatures and several enchant types are reported. The investigation of etch pits in the twinned Y AlO3 and NdGaO3 crystals showed that twins are formed during a growth proce ss. In the [110]-pulled NdGaO3 crystals the discrepancy between the twin an d matrix parts of a crystal is accommodated by the dislocation congestion a nd the dislocation low-angle boundaries whereas in [010]-pulled YAlO3 cryst als the microcracks perform this function.