Inter-American Materials Collaboration (CIAM): West Virginia University - Pontificia Universidad Catolica de Chile Collaboration on Multifunctional Materials David Lederman, West Virginia University, DMR 0502825 • Collaboration between Physics Depts of WVU in the US and PUC in Chile • Focus on growth via molecular beam epitaxy, characterization and properties of multifunctional ferroelectric/ semiconductor heterostructures • Successfully grew ferroelectric YMnO 3 /GaN bilayers at WVU [Appl. Phys. Lett. 88, 132906 (2006) ] which are – Ferroelectric at room temperature – Magnetic at low temperatures • Characterization made at both WVU (ferroelectric measurements, x-ray structure, RHEED, AFM) and PUC (Auger spectroscopy) • Also studied self-organization of magnetic dots on insulators via in-situ, ultra high vacuum, high temperature scanning probe microscopy ] 110 [ ] 001 [ ] 10 1 [ Department of Physics -2000 -1000 0 1000 2000 -2 0 -1 0 0 10 20 P o la riza tio n ( C/cm 2 ) F ie ld (kV /cm ) 0 20 40 60 80 100 120 140 0 500 1000 1500 T (K ) M om ent(em u/cm -3 ) 0 .00 0 .05 0 .10 FC ZFC M om e nt ( B /M n) a b c x y z 1 ML Mn 1 ML Y 1 ML Mn 1 ML Y 1 ML Mn 1 ML Y GaN (0001) c-axis (a) Oxide MBE growth chamber (b) Diagram of the YMnO 3 layer-by-layer growth (c) In-plane x-ray diffraction of YMO film (blue) and GaN (cyan), demonstrating epitaxial growth (d) Field-cooled (FC) and zero-field-cooled (ZFC) magnetization of YMO film as a function of temperature. (e) Polarization of YMO film as a function of electric field at room (f) Auger spectra of three YMO films with different stoichiometries.