Formation and destruction of cube texture in MgO films using ion beam assisted pulsed laser deposition

Biaxially textured MgO thin films were deposited on amorphous substrates using ion beam assisted pulsed laser deposition. The development of the texture and microstructure was investigated with electron diffraction and atomic force microscopy. After the first few nanometers of growth, a sharp nucleation texture is observed. During further growth a texture change takes place, leading to two texture components, one in the 〈220〉 direction and the other in the 〈111〉 direction parallel to the substrate normal. In both cases the 〈200〉 direction is parallel to the ion beam. This texture change can be explained in terms of the highly anisotropic sputter rate observed in experiments on single crystals, leading to grains having a 〈200〉 direction parallel to the ion beam during growth being preferred. Without ion beam assistance during further growth, one of the two texture components dominates.