In continuation of the electron microscopical work on CrBr3 done by Matricardi et. al. we have applied a special type of liquid helium specimen stage, which has permitted application of a horizontal magnetic field in the specimen region. During observation of the specimen we have been able to apply fields up to 60 Oe, without observation fields up to 600 Oe.In general the observations of Matricardi et.al. have been confirmed, especially the contrast, size and shape of the domains, their non-appearance in in-focus micrographs and micrographs taken above the Curie point. On the other hand occasional regions of the foil, where the contrast disappears (Fig. 1a] are not thought to be chemical inhomogeneities. Such regions can exhibit strong domain contrast if the foil orientation changes slightly, as in our case by the thermal strains occuring in warming-up the specimen to approx. 60 K and cooling it down again.
Surface material dependence of beam-tilted-foil orientation and alignment
