Multifunctional Magnetic Oxide Thin Films

When: Thursday, November 14, 2013 at 4:00 pm
Where: DA 114
Speaker: Caroline Ross
Organization: Department of Materials Science and Engineering, Massachusetts Institute of Technology
Sponsor: Joint Physics and Chemical Engineering Colloqium

This seminar will describe the growth and properties of thin films of magnetic perovskites, magnetic garnets, and multiferroic perovskite-spinel nanocomposites made using combinatorial pulsed laser deposition. These oxide thin films offer intriguing physics as well as useful applications. Magnetic perovskites are made by substituting 5-50% of transition metals into strontium titanate to produce Sr(Ti,M)O3, with M = Fe, Co, Cr, Cu, Ni. Some of these materials are magnetic well above 500˚C, and show strong magnetoelastic anisotropy as well as Faraday rotation. Self-assembled perovskite-spinel nanocomposites consist of magnetic CoFe2O4, NiFe2O4 or MgFe2O4 spinel pillars in a ferroelectric BiFeO3 matrix. The magnetic properties of the pillars are governed by magnetoelasticity, and their locations can be templated by substrate patterning, producing well-controlled multiferroic nanocomposites. Magnetic garnets such as CeYIG are grown as single phase films on Si using a YIG seed layer, and their integration into isolators for near-IR wavelengths based on a ring resonator will be described.