Four kinds domain study of pure and Mn-doped PbTiO3 single crystals by atomic force and Kelvin force microscopy

Surface gradients and electrical potentials of 90° a-c and 180° c-c domains of pure, Mn-doped PbTiO₃, single crystals have been investigated by atomic force and Kelvin force microscopy. In the 90° a-c domains, regular gradients with angles of 3.0° to 3.24° in pure PT, 2.98° to 3.34° 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, θ(deg.)=2tan^-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° 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