Crystal growth of β’—Gd2（Mo4）3 and in situ observation of its domain structure by the microscope and the synchrotron X—ray topography

We report that β’-Gd2(MoO4)3 crystals have been grown by the Czochralski(CZ) method.We studied the growth conditions fo β’-Gd2(MoO4)3 crystal.A compatison between the resistance-heated method and radio frequency induction-heated method is described.Also,the in situ observation of the domain structure by the microscope and by synchrotron radiation X-ray topography under the conditions of DC polarization voltage and tempertature change were carried out.Experiments showed that multidomain structure including ferroelectric and ferroelastic domains occurred in β’-Gd2(MoO4)3 cystal.Usually ferroeletiric domains appeared in the as-grown crystal and ferroelastic domains appeared in the polished thinner piece.Both ferroelectric and ferroelastic domains disappeared when the temperature of the crystal piece was higher than the Curie tempperature Tc and they could be reproduced when the temperature of the crystal piece was lowered below TC.When a DC polarization voltage ranging from 150 to 500V was applied on a c-axis β’-Gd2(MoO4)3 piece having a thickness of 0.5mm ,the multidomain would gradually transform to a single domain.This resual means that it is possible to make a periodically poled β’-Gd2(MoO4)3 crystal.2001 Elsevier Science B.V.All rights reserved.