TEM METHOD FOR IDENTIFICATION OF DOMAINS IN MATERIALS WHICH UNDERGO A PM3M-] R3C OR R3BARC PHASE-TRANSITION

The c‐axis of the domains formed by a Pm3m → R3c or R3c phase transition may lie along any of the four 〈111〉C directions of the cubic phase. It is shown that the orientation of the c‐axis can be determined by TEM by examining whether two suitable 1/2 {113}C superlattice reflections are allowed or forbidden in the trigonal phase. As an example, the method is used to examine domains in LaAlO3. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA