Orientation control and self-assembled nanopyramid structure of LaFeO3 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.