Four kinds domain study of pure and Mn-doped PbTiO/sub 3/ single crystals by atomic force and Kelvin force microscopy

Surface gradients and electrical potentials of 90/spl deg/ a-c and 180/spl deg/ c-c domains of pure, Mn-doped PbTiO/sub 3/, single crystals have been investigated by atomic force and Kelvin force microscopy. In the 90/spl deg/ a-c domains, regular gradients with angles of 3.0/spl deg/ to 3.24/spl deg/ in pure PT, 2.98/spl deg/ to 3.34/spl deg/ in Mn-doped PT at the domain boundary were measured in as-grown crystals. The angles of gradient are varied by the crystal tetragonality (c/a) and obeyed the following equation, /spl theta/(deg.)=2tan/sup -1/((c/a)-90. The difference of electrical potential in a- and c-domains was 2.4 to 9.3 mV, in which a-domains arranged sideways to the surface and c-domains aligned perpendicular to the surface. In the 180/spl deg/ c-c domain, the trapezoidal forms with a step of 80 to 100 nm were constructed and the difference of electrical potential between the top and bottom of the trapezoidal step was 15 mV due to the each plus and minus surfaces in c-domains.