Domain structures of PbTiO/sub 3/ single crystal and La-modified PbTiO/sub 3/ thin film by Kelvin force microscope

In PbTiO/sub 3/ single crystals, 90/spl deg/ a-c, 90/spl deg/ a-a, 180/spl deg/ a-a, 180/spl deg/ c-c domain and connected domain structures have been investigated using a Kelvin force microscope. A new discrimination method for classifying these domain structures was proposed by combining surface gradient, surface electrical potential and difference of step among the domains by etching rate. Two kinds of c domains, called +c domain and -c domain, were measured separately. Similarly, the 180/spl deg/ c-c domain in spontaneously poled (Pb,La)TiO/sub 3/ thin film on [100]Pt/[100]MgO was discussed with pyroelectric measurements.