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 YMnO3/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

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Department of Physics

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(a) Oxide MBE growth chamber(b) Diagram of the YMnO3layer-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 temperature.

(f) Auger spectra of three YMO films with different stoichiometries.

Department of Physics

Inter-American Materials Collaboration (CIAM): West Virginia University - Pontificia Universidad Catolica de Chile Collaboration

on Multifunctional Materials David Lederman, West Virginia University, DMR 0502825

Education:• This project has involved graduate students Jorge Espinosa, Guerau Cabrera, Sandeep Chandril, and Cameron Keenan.• Postdoc Yewhee Chye was also involved with DoD funding• PUC-Chile graduate student Esteban Ramos performed analysis in Chile. • Exchanges between PUC and WVU occurred in travel by Espinosa and Keenan to LAW3M conference in Renaca, Chile, Dec 2005, to present posters. This was followed by two weeks of research at PUC. PUC grad student Esteban Ramos visited WVU labs Jan-Feb 2006 to aid in sample growth and characterization.• REU supplement involved undergraduate students Matt Koepke (WVU, 2005) and John McLane (Bethany College, WV, summer 2006).

Societal Impacts:• Multifunctional materials may result in faster and better electronic materials that can be used as sensors, memories, and actuators, all integrated in a single device• Exchange between PUC and WVU reinforces WVU's underrepresented minority outreach efforts, especially those directed toward Latino students

John McLane taking a breakGuerau Cabrera working on the x-ray diffractometer