PARADIM REU Project Title: STEM Imaging and Composition Mapping of Multiferroic Oxides

PARADIM REU Project Title: STEM Imaging and Composition Mapping of Multiferroic Oxides

Materials that couple electric and magnetic ordering create interesting possibilities for the next generation of data storage technologies. However, there are few of these multiferroic materials that exist at room temperature, and even fewer with strong, coupled polarization and magnetization. One promising avenue to develop these materials is through oxide molecular beam epitaxy, which can generate new combinations of properties through heterostructures and interface phases. Here, we combine the ferroelectric LuFeO3 with the ferrimagnetic CoFe2O4 into a superlattice to develop a material with spontaneous polarization and magnetization above room temperature. To study how these materials are layered at the atomic scale, we use scanning transmission electron microscopy (STEM) combined with x-ray energy dispersive spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). We map the elemental profiles through the film and across the bottom electrode to determine the relation between interdiffusion and growth conditions, which provides critical feedback for further growths.