Dr. John Freeland
Advanced Photon Source
Argonne National Laboratory
|TITLE:||"Harnessing Complex Oxide Heterostructures to Create Novel Materials"|
|DATE:||Thursday, April 5, 2012|
|PLACE:||Building 212 / A-157|
Refreshments will be served at 10:45 a.m.
ABSTRACT: Functional oxides based on the transition metal series display a wide spectrum of remarkable electronic properties including magnetism, superconductivity and metal-insulator transitions, which offer potential important properties for practical applications in meeting the energy challenges of the future. These novel properties arise from the interaction between the charge, orbital, spin, and lattice degrees of freedom. One key to controlling these properties lies in the ability to control the underlying structure. By using epitaxial growth to strain oxide crystal structures, thin film synthesis offers novel route to control oxide structure in ways not attainable in the bulk counterparts. This allows one to access new regions of phase to explore emergent states not present in bulk form. Extending this to ultrathin heterostructures then offers the ability to harness dimensionality as an additional knob to control the interactions of strongly correlated electrons. Here I will highlight our recent work on complex oxide heterostuctures such as using strain and dimensionality to control orbital configurations in RNiO3 [1-3] and mixing of ferromagnetism and superconductivity in cuprate-manganite superlattices[4-6]. In the end, I will also touch on our new efforts on understanding the synthesis and function of layered oxides funded by the Materials for Energy initiative.
Work at Argonne is supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
 J. Liu et al. Phys. Rev. B 83, 161102 (2011).
 J. Chakhalian et al. Phys. Rev. Lett. 107, 116805 (2011).
 J.W. Freeland et. al. Europhysics Letters 96, 57004 (2011)
 J. Chakhalian, J.W. Freeland et. al. Nature Physics 2, 244 (2006).
 J. Chakhalian, J.W. Freeland et. al. Science 318, 1114 (2007).
 J.W. Freeland et. al. Appl. Phys. Lett. 90, 242502 (2007).