The project consists of the study of various single and multilayer ferrite systems with potential suitability for magneto-optic (MO) data storage. The class of materials chosen are orthoferrites which exhibit high coercive fields and low saturation magnetisation. A high coercive field and substantial Faraday rotation of polarised light are essential for good MO data storage.
The main aim is to produce orthoferrite films using pulsed laser deposition, studying the magnetic and magneto-optic properties. Of particular interest will be the dependence of growth conditions on the coercive field, saturation magnetisation and the orientation of the magnetic moments with respect to the sample plane and crystalline axes. Depositing a soft magnetic layer (spinel) adjacent to the hard magnetic layer (orthoferrite) should give rise to a range of possible magnetic couplings between the layers, through an intervening oxide layer, allowing an engineering of the global magnetic properties of the whole sample in order to combine high saturation magnetisation with high coercive fields.