Wells, Barrett

Research Interests
Studies of high temperature superconductors, magnets, ferroelectrics in transition metal oxide compounds where strong electron correlations dominate the physics. We apply a wide range of experimental probes to materials made in our laboratory. Materials capabilities include the control of oxygen stoichiometry using electrochemistry and ozone treatments and the growth of high quality oxide films. Film studies include how the strain, low-dimensionality, and constraint of epitaxy control material properties and phase transitions.

Research highlights: early studies of the symmetry of the superconducting gap in copper oxide superconductors with Angular-Resolved Photoemission, the study of the dispersion of a single hole in an insulating copper-oxide - parent material to high temperature superconductors, studies of oxygen staging and large-scale electronic phase separation in oxygen doped La_2-xSr_xCuO_4+y high temperature superconductor, control of structural phase transitions via strain and epitaxy in ferroelectric and related films, separation of finite-size and strain effects on the magnetism of ferromagnetic oxide films.

Education

• Ph.D., Applied Physics, Stanford University, 1992
• M.S., Applied Physics, Stanford University, 1990
• B.S., Physics, Stanford University, 1986

Experience

• 1998-present: Professor, Department of Physics, University of Connecticut
• 1998-1999: Guest Researcher, Brookhaven National Laboratory
• 1996-1998: Member - Technical Staff, Boeing Corporation
• 1992-1996: Postdoctoral Fellow, Department of Physics, MIT

Honors

• 2003-2009 National Science Foundation CAREER Award
• 2002-2007 Cottrell Scholar by Research Corporation
• 2000-2002 Sloan Foundation Research Fellow

Recent Publications

1. L. Udby, N. H. Andersen, F. C. Chou, N. B. Christensen, S. B. Emery, K. Lefmann, J. W. Lynn, H. E. Mohottala, Ch. Niedermayer, and B. O. Wells, Magnetic ordering in electronically phase-separated La_2-xSr_xCuO_4+y : Neutron diffraction experiments, Phys. Rev. B 80, 014505 (2009).
2. C. K. Xie, J. I. Budnick, W. A. Hines, B. O. Wells, and J. C. Woicik, Strain-induced change in local structure and its effect on the ferromagnetic properties of La_0.5Sr_0.5CoO₃ thin films, Appl. Phys. Lett. 93, 182507 (2008).
3. C. K. Xie, J. I. Budnick, W. A. Hines, B. O. Wells, Feizhou He, and A. R. Moodenbaugh, Direct evidence for the suppression of charge stripes in epitaxial La_1.67Sr_0.33NiO₄ films, Phys. Rev. B 77, 201403(R) (2008).
4. Hashini E. Mohottala, Barrett O. Wells, Joseph I. Budnick, William A. Hines, Christof Niedermayer, Christian Bernhard, Arnold. R. Moodenbaugh, Fang-Cheng Chou, Electronic phase separation in La_2-xSr_xCuO_4+y Nature Materials 5, 378 (2006).
5. F. He, B. O. Wells, and S. M. Shapiro, Strain Phase Diagram and Domain Orientation in SrTiO₃ Thin Films, Phys. Rev. Lett. 94, 176101 (2005).