Orientation control and self-assembled nanopyramid structure of LaFeO ₃ films epitaxially grown on SrTiO₃ (001) substrates

Epitaxial films of LaFeO₃ (LFO) were grown on SrTiO₃ (001) (STO) substrates using pulsed laser deposition. Two epitaxial orientations were observed: α where LFO(110)STO(100) and Β where LFO(001)STO(100). By controlling the deposition conditions, LaFeO₃ films could be grown with just the α orientation or with simultaneous α and Β orientations in which the film consisted of a self-assembled array of nanoscale Β pyramids embedded in a matrix of α. The microstructure and growth mechanism of the films and their exchange-bias with a Co overlayer are discussed.