Geoffrey Rojas (Shelburne)
Geoffrey Rojas headshot

Geoffrey Rojas (Shelburne)

Research Associate, Characterization Facility

Contact

612-301-1800
garojas@umn.edu
Shepherd Labs
Room 85
100 Union St SE
Minneapolis, MN 55455

Education

  • Ph. D. in Physics & Astronomy, University of Nebraska-Lincoln
  • M. S. in Physics & Astronomy, University of Nebraska-Lincoln
  • B. S. in Physics, Augsburg College

Professional Background

  • 2013 - 2015: Postdoctoral Associate, Department of Chemical Engineering & Materials Science, University of Minnesota
  • 2011 - 2013: Postdoctoral Associate, Imaging & Characterization User Facility, Oak Ridge National Laboratory
  • 2005 - 2011: Research Assistant, Department of Physics & Astronomy, University of Nebraska-Lincoln

Biography

Geoff Rojas is a condensed matter physicist with a Ph.D. from the University of Nebraska-Lincoln. His graduate work was followed by a two-year postdoctoral appointment at the Imaging Characterization user facility at Oak Ridge National Laboratory. His research focused on in situ growth and characterization of ultrathin films using a variety of techniques include scanning tunneling microscopy, local probe spectroscopy, x-ray diffraction, and x-ray and ultraviolet photoelectron spectroscopy. He came to the University of Minnesota in 2013 as a postdoctoral associate to study interface chemistry, printing techniques, and scanning force microscopy.

Research Interests

A committed researcher at the University of Minnesota, his interests include the development of multi-dimensional surface probe techniques, nanoscale characterization of mechanical and chemical properties of active biological systems, and the in situ study of functional materials using both local and integral spectroscopy methods.

Selected Publications

  • Rojas, G. A.; Wu, Y.; Haugstad, G.; Frisbie, C. D. Measuring the Thickness and Potential Profiles of the Space Charge Layer at Organic/organic Interfaces under Illumination and in the Dark by SKPM. ACS Appl. Mater. Interfaces 2016, acsami.6b00367.
  • Wu, Y.; Chew, A. R.; Rojas, G. A.; Sini, G.; Haugstad, G.; Belianinov, A.; Kalinin, S. V.; Li, H.; Risko, C.; Brédas, J.-L. Salleo, A.; Frisbie, C. D. Strain Effects on the Work Function of an Organic Semiconductor. Nat. Commun. 2016, 7, 10270.
  • Rojas, G. A.; Ganesh, P.; Kelly, S. J.; Sumpter, B. G.; Schlueter, J. A.; Maksymovych, P. Ionic Disproportionation of Charge Transfer Salt Driven by Surface Epitaxy. J. Phys. Chem. C 2013, 117 (38), 19402-19408.
  • Rojas, G. A.; Chen, X.; Kunkel, D.; Nitz, J.; Xiao, J.; Dowben, P. A.; Simpson, S.; Zurek, E.; Enders, A. Surface State Engineering of Molecule-Molecule Interactions. Phys. Chem. Chem. Phys. 2011, 14 (14), 4971-4976.
  • Chen, X.; Yang, S.; Kim, J.-H.; Kim, H.-D.; Kim, J.-S.; Rojas, G. A.; Skomski, R.; Lu, H.; Bhattacharya, A.; Santos, T.; Guisinger, N.; Bode, M.; Gruverman, A.; Enders, A. Ultrathin BaTiO3 Templates for Multiferroic Nanostructures. New J. Phys. 2011, 13 (8), 083037.
  • Rojas, G. A.; Chen, X.; Bravo, C.; Kim, J. H.; Kim, J.-S.; Xiao, J.; Dowben, P. A.; Gao, Y.; Zeng, X. C.; Choe, W.; Enders, A. Self-Assembly and Properties of Nonmetalated Tetraphenyl-Porphyrin on Metal Substrates. J. Phys. Chem. C 2010, 114 (20), 9408-9415.
  • Shand, P. M.; Bohnet, J. G.; Goertzen, J.; Shield, J. E.; Schmitter, D.; Shelburne, G. A.; Leslie-Pelecky, D. L. Magnetic Behavior of Melt-Spun Gadolinium. Phys. Rev. B 2008, 77 (18), 1-11.
  • Morales, M. A.; Skomski, R.; Fritz, S.; Shelburne, G. A.; Shield, J. E.; Yin, M.; O'Brien, S.; Leslie-Pelecky, D. L. Surface Anisotropy and Magnetic Freezing of MnO Nanoparticles. Phys. Rev. B 2007, 75 (13), 1-5.