CoFe 2 O 4 thin films with large perpendicular magnetic anisotropy were obtained by pulsed laser deposition on Si(100) substrates with MgO buffer layers. Transmission electron microscopy study reveals the columnar structure of these CoFe2O4 films and confirms their (100) texture. Magnetic properties of these films have been investigated in the function of substrate temperature and film thickness. A perpendicular coercivity as high as 7.8 kOe has been achieved in the CoFe2O4 film deposited at 700 °C, with a thickness of 50 nm and a grain size of 30 nm. The high coercivity mechanism is possibly associated with the magnetocrystalline anisotropy, the strain anisotropy, the shape anisotropy due to the columnar structure, and also the appropriate grain size approaching the single-domain critical value.

Selective growth of single-oriented (2 2 0), (2 0 0) and (1 1 1) MgO films on Si (1 0 0) substrates without buffer layers were obtained with a single crystal MgO target by pulsed laser deposition. All the films are very smooth and free of droplets, especially the surface of (2 2 0) and (2 0 0) oriented MgO films which are atomic-scale smooth. High resolution transmission electron microscopy was used to analyse the interfaces between MgO and Si under various conditions.

The environment-friendly synthesis and property modulation of two-dimensional organic–inorganic halide perovskite (2D OHP) single crystals with large sizes and high quality are important for the fabrication of optoelectric devices.

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