Multiferroics have attracted a remarkable attention in the last decade for their possible use in memory devices because of the coupling between different order parameters, more specifically ferromagnetism, ferroelectricity and ferroelasticity. The investigation of the relation between the ferroelectricity and (anti)ferromagnetism in multiferroics is important for the development of the multistate logic in a single device. Use of the multiferroics in memory devices or logic architecture might result in a low power consuming devices as the writing information can be done by applying voltage instead of current or field as usually used for Magnetic Random Access Memory and reading data can be done magnetically. To achieve this purpose, in other words, changing the magnetic field direction by applying voltage or vice versa, the coupling between the two order parameters in multiferroics should be elucidated well.
Nowadays, one of the few promising room temperature multiferroic is BiFeO3 which had gone under an extensive investigation in the last decade after discovering the large spontaneous ferroelectric polarization in the high quality single crystal thin film form. Ferroelectric properties of BiFeO3 was studied predominantly whereas the magnetic point of view has been lacking in the literature. Therefore one of the main objectives of the project is to find out the relation between the ferroelectricity and the (anti)ferromagnetism in multiferroics, starting with BiFeO3.
BiFeO3 is a ferroelastic material that is associated with the ferroelectricity so that with the magnetism. Therefore, depending on the structural deformation orientation, different domains and domain walls can form in BiFeO3. As the structure and the atomic positions change the physics properties of correlated oxide systems, these domain walls becomes important and might show different properties. Hence, it is important to have a control over the manufacturing of certain domain wall types and their functional properties. In our group, we use Pulsed Laser Deposition method to grow thin films of BiFeO3 and currently investigating the effects of interface engineering on the BiFeO3 growth.