Hamidreza Khassaf

Fabrication of multiferroic thin films on single crystal substrates with conducting oxide electrodes and their electrical characterization

Functional thin films are used in integrated circuits for a variety of purposes such as storing data in the form of charge and/or electric/magnetic dipoles (Dipole up:0, dipole down:1), infrared sensors, tunable dielectric layers in wireless communication, piezoelectrical systems and etc. Very recently, oxides, namely ?multiferroics? that exhibit both electric dipoles (polarization) and magnetic dipoles (magnetization) have come to the attention of the scientific community (they were known since the 50?s and 60?s but did not find use) where the two properties are coupled to each other, often mentioned as ?spin-charge coupling?. Experimental studies on these materials demonstrated that an external voltage can change the magnetization state of the material and an external magnetic field can change the polarization, hence the dielectric constant of the material. There is now ongoing effort in integrating such materials into micro- and nanoelectronics, especially for memory devices and wireless communication technologies.

This project focuses on the coherent growth (near epitaxial) of multiferroic materials on single crystal substrates via chemical precursor methods followed by characterization of their electrical and magnetic properties. Another target of the project is to grow conducting oxides epitaxially on single crystal substrates in thin film form and correlate their conductivity to the internal stresses occurring due to the film-substrate misfit.