Twin-free Epitaxial LaFeO3 Films Grown on Orthorhombic GdScO3(110)o Substrates

Epitaxial LaFeO3 (LFO) thin films have been grown on orthorhombic GdScO3 (GSO) substrate by using the pulsed laser deposition (PLD) method. Surface morphology of the LFO film exhibits atomically controlled surface characteristics with steps and terraces. The structural information is investigated comprehensively through the X-ray diffraction (XRD) analysis. The orthorhombicity of the GSO substrate suppresses twin formation resulting in twin-free LFO films. The untwinned LFO films are fully strained in a monoclinic structure up to 100 nm thickness. As the film thickness further increases, the strain is abruptly relaxed above 100 nm without considerable twinning and the monoclinic distortion becomes minimal as like the orthorhombic bulk LFO.