V. Ovidiu Garlea

V. Ovidiu Garlea

Position: Instrument Scientist

Instrument: Hybrid Spectrometer

Division: Quantum Condensed Matter Division

Facility: Spallation Neutron Source

Contact: garleao@ornl.gov or (865) 202-7546

Education

PhD in Condensed Matter Physics, Joseph-Fourier University, in Grenoble, France

Research

Dr. Garlea studies strongly correlated electron systems and quantum magnets using neutron and x-ray diffraction and inelastic neutron scattering technique. The research topics he is currently pursuing include:

  • exotic magnetic ground states, such as incommensurate magnetic ordering and spin-liquid, arising from competing interactions in geometrically frustrated magnets
  • magnetic phase diagrams of functional materials, such as multiferroics, magnetocaloric materials, and shape-memory alloys
  • orbital degeneracy and the interplay of spin, orbital and lattice degrees of freedom in transition metal systems
  • magnetic excitations and magnetic field-induced condensation of magnons in low dimensional spin-gapped quantum systems

Dr. Garlea is currently co-responsible for the HYSPEC spectrometer, a new concept in high-flux inelastic neutron spectrometry that allows for innovative studies of atomic-scale dynamical properties of crystalline materials. Dr. Garlea is adjunct associate professor at the Department of Materials Sciences and Engineering at the University of Tennessee, and is holding a courtesy appointment with the Department of Chemistry & Biochemistry at Florida State University. From 2007 to 2013, Dr. Garlea was the lead instrument scientist at the HB2a Neutron Powder Diffractometer at the High Flux Isotope Reactor (HFIR), at ORNL. Prior to that appointment, he held postdoctoral positions at the Center for Neutron Scattering at ORNL, at the Ames Laboratory, and at the Synchrotron Light Laboratory ELETTRA, in Italy. During the PhD, Dr. Garlea has worked at the Laboratoire de Cristallographie, CNRS, in Grenoble, France. He also worked at the National Institute for Research and Development for Isotopic and Molecular Technology, and at the Center for Solid State Physics, associated with Babes-Bolyai University, in Cluj Napoca, Romania.

Dr. Garlea is interacting with dozens of visiting scientists annually, and greatly enjoys his involvement in science education and outreach. Over the years he has hosted and mentored a number of undergraduates, graduate students and postdoctoral fellows from different universities including Florida State University, University of Tennessee, University of Virginia, and Louisiana State University. He has been actively involved with the National School on Neutron and X-ray Scattering, and with the Undergraduate School on Magnetism and Magnetic Materials hosted at FSU.

Dr. Garlea has published more than 80 research articles in international peer reviewed journals, has presented numerous invited talks at international conferences, and has been the organizer and lecturer for a workshop series on Representational Analysis and Magnetic Structure Determination by Neutron Diffraction.

Selected Publications

  • D. Fobes, I. A. Zaliznyak, Z. Xu, R. Zhong, G. Gu, J. M. Tranquada, L. Harriger, D. Singh, V. O. Garlea, M. Lumsden, B. Winn, Ferro-orbital ordering transition in iron telluride Fe1+yTe, Phys. Rev. Lett. 112, 187202 (2014)
  • V. O. Garlea, L. D. Sanjeewa, M. A. McGuire, P. Kumar, D. Sulejmanovic, J. He, S.-J. Hwu, Complex magnetic behavior of the sawtooth Fe chains in Rb2Fe2O(AsO4)2, Phys. Rev. B 89, 014426 (2014)
  • A. B. Karki, V. O. Garlea, R. Custelcean, S. Stadler, E. W. Plummer, R. Jin, Interplay between superconductivity and magnetism in Fe1-xPdxTe, Proc. Natl. Acad. Sci. USA 110, 9283 (2013)
  • S. Calder, V. O. Garlea, D. F. McMorrow, M. D. Lumsden, M. B. Stone, J. C. Lang, J.-W. Kim, J. A. Schlueter, Y. G. Shi, K. Yamaura, Y. S. Sun, Y. Tsujimoto, A. D. Christianson, Magnetically Driven Metal-Insulator Transition in NaOsO3, Phys Rev Lett 108, 257209 (2012)
  • V. O. Garlea, A. T. Savici, R. Jin, Tuning the magnetic ground state of a triangular lattice system Cu(Mn1-xCux)O2, Phys Rev B 83, 172407 (2011).
  • V. O. Garlea, A. Zheludev, L.-P. Regnault, J.-H. Chung, Y. Qiu, M. Boehm, K. Habicht, and M. Meissner, Gap excitations in a four-leg Heisenberg spin tube antiferromagnet, Phys. Rev. Lett 100 037206 (2008)
  • V. O. Garlea, R. Jin, D. Mandrus, B. Roessli, Q. Huang, M. Miller, A. J. Schultz, and S. E. Nagler, Magnetic and orbital ordering in the spinel MnV2,O4, Phys. Rev. Lett. 100 066404 (2008)
  • V. O. Garlea, A. Zheludev, T. Masuda, H. Manaka, L.-P. Regnault, E. Ressouche, B. Grenier, J.-H. Chung, Y. Qiu, K. Habicht, K. Kiefer and M. Boehm, Excitations from a Bose-Einstein condensate of magnons in coupled spin ladders, Phys. Rev. Lett. 98 167202 (2007)
  • V. O. Garlea, S. E. Nagler, J. L. Zarestky, C. Stassis, D. Vaknin, P. Kögerler, D. F. McMorrow, C. Niedermayer, D. A. Tennant, B. Lake, Y. Qiu, M. Exler, J.Schnack, and M. Luban, Probing high-symmetry spin frustration in magnetic nanomolecules by inelastic neutron scattering, Phys. Rev. B 73 024414 (2006)
  • V. O. Garlea, J. L. Zarestky, C. Y. Jones, L.-L. Lin, D. L. Schlagel, T. A. Lograsso, A. O. Pecharsky, V. K. Pecharsky, K. A. Gschneidner Jr., and C. Stassis, Neutron Diffraction Studies of the Tb5SixGe4-x Magnetoelastic Compounds with x = 2.2 and x = 2.5, Phys. Rev. B 72 104431 (2005)