ORIGIN OF IMPERFECTIONS IN [100]SRLAALO4 CRYSTALS

In Czochralski-grown SrLaAlO4 crystals with (100) orientation, (001) p lanar faults extending through tile entire crystal boule can frequentl y be observed. Chemical etching and transmission electron microscopy i ncluding energy dispersive X-ray spectroscopy were used to characteris e their nucleation sites, these being located in tile upper part of ti le crystal cone. Three serious sources were found: (1) lateral (001) f acets, (2) grown-in defects in the seed, and (3) small particles of a second phase in tile interior of the cone. These particles were identi fied as trigonal and cubic form of lanthanum oxide with a different Sr content.