OBSERVATION OF DOMAIN-STRUCTURES IN TETRAGONAL PB(ZRXTI1-X)O3 SINGLE-CRYSTALS BY CHEMICAL ETCHING METHOD

Domain structures in tetragonal Pb(ZrxTi1-x)O3 (PZT) single crystals etched by HF + HCl solution were observed by means of a scanning electron microscope. The relationship between the etch patterns of pseudocubic {100} faces and spontaneous polarization vectors was examined using micro-Raman spectroscopy and electron channeling patterns. Both the a-face and the positive c-face are quickly etched, but the former results in a rough surface while the latter results in a smooth one. The negative c-face is rather slowly etched. Another type of etch pattern with a wedge-shaped section was observed; this is usually observed in PZT ceramics but has not been reported in BaTiO3. This pattern can be explained by the difference in etch rates between various {100} faces and the peculiar domain structures which consist of a single domain region with narrow or wedge-shaped 90-degrees domains. It is assumed that such a domain structure is, although unstable under electrical stress, stable under mechanical stress.