Epitaxial Electrodeposition of Orthorhombic α-PbO[sub 2] on (100)-Oriented Single Crystal Au

Epitaxial films of orthorhombic lead dioxide α-PbO 2 (Pbcn, a = 0.4971, h = 0.5956, and c = 0.5438 nm) were electrodeposited at room temperature on a [100]-oriented single crystal Au substrate (cubic, Fm3m, a = 0.4079 nm). The values of lattice mismatch are 21.9, 46.0, and 33.3% in the a, b, and c directions of α-PbO 2 , respectively. The films are [100]-oriented, with the a axis perpendicular to the substrate. Depending on the preparation conditions, the film was found to form two different in-plane orientations, with the unit cell of the PbO 2 structure rotated either 45 or 11.5° relative to the substrate. For the films deposited at low current density, only the first type of the in-plane texture is observed, while at high current densities both types are present in comparable amounts.