Robert McQueeney

Associate Scientist, Condensed Matter Physics, Ames Laboratory Assistant Professor, Dept. of Physics and Astronomy A305 Physics Iowa State University Ames, IA 50010 Phone: 1-515-294-3545 mcqueeney@ameslab.gov

PERSONAL HISTORY (VITA)

2003	-	Present	Assistant Professor, Dept. of Physics and Astronomy, Iowa State University
2003	-	Present	Associate Scientist, Ames Laboratory
1998	-	2003	Staff Member, Lujan Center, Los Alamos National Laboratory
1998			(summer) Visiting Scientist, Dept. of Materials Science & Engineering, California Institute Of Technology
1996	-	1998	Postdoctoral Fellow, Lujan Center, Los Alamos National Laboratory
1996			Ph. D. (Physics), University of Pennsylvania
1991			B. S. (Physics & Chemistry), University of Connecticut

HONORS, AWARDS, AND PROFESSIONAL ACTIVITIES

• American Physical Society
• American Association for the Advancement of Science
• Neutron Scattering Society of America
• LANSCE User Group
• SNS/HFIR User Group
• ARCS (SNS), Instrument Development Team, Executive Committee member
• SEQUOIA (SNS), Instrument Development Team, member
• SNS/HFIR User’s Group Executive Committee, 1998-2002
• 2002 American Conference on Neutron Scattering, organizing committee
• 2003 National Nuclear Security Administration Award for Excellence in Research (LANL)

RESEARCH INTERESTS

My primary area of research is in condensed matter physics. In particular, I am interested in the fundamental understanding of exotic ground states in condensed matter systems, how they arise, and the nature of phase transitions between different ground states. Neutron scattering is arguably the most powerful experimental technique available to address these questions and is my area of expertise. Neutron diffraction techniques can be used to determine both crystalline and magnetic structures (sometimes simultaneously) as they vary with temperature, pressure, and applied external magnetic field and is an indispensable tool for mapping out phase diagrams of materials. In addition, inelastic neutron scattering techniques can probe lattice, magnetic, and electronic excitations and allow for a better understanding of different ground states by observing the fundamental collective excitations and fluctuations out of the ground state, and the relationship of these collective excitations/fluctuations to phase transitions. Out of the vast number of condensed matter systems that can be addressed by these techniques, I focus my research on the broad class of materials known as correlated systems. In many materials, the electrons, phonons (lattice vibrations), and spins can be treated independently with small residual interactions resulting in quasiparticles, which have renormalized properties (such as the effective mass of a conduction electron), but can still be understood in a single-particle picture. In correlated systems, the interaction between these particles is strong and the concept of a quasiparticle breaks down and many-body effects become important. The strongest and most important of these interactions, the electron-electron interaction, forms the starting point for a variety of correlated electron systems that have both unusual ground states and excitations. This is a very active area of condensed matter research and includes systems such as high-temperature superconductors, heavy fermions, colossal magnetoresistive materials, Mott insulators, and complex magnetic materials.

PROJECTS

Elastic and magnetoelastic behavior of Fe-Ga alloys

Magnetism and magnetoelastic coupling in rare-earth germanides

Lattice and spin dynamics of the Verwey transition
Metal-insulator transition in the vanadium Magneli series

Neutron diffraction studies of rare-earth intermetallic compounds

Spin and Orbital Ordering in Y_1-xLa_xVO₃ Perovskites

Structural Anomalies induced by spin-state transition in PrCoO₃
Lattice dynamics of high-temperature superconductors

SELECTED PUBLICATIONS

FULL PUBLICATION LIST (PDF)

 

• Investigation of the presence of charge order in magnetite by measurement of the spin wave spectrum,
              R. J. McQueeney, M. Yethiraj, W. Montfrooij, J. S. Gardner, J. Honig,
              Phys. Rev. B 73, 174409 (2006).
• Magnetic Structure of Gd₅Ge₄,
              L. Tan, A. Kreyssig, J. W. Kim, A. I. Goldman, R. J. McQueeney, D. Wermeille, B. Sieve, T. A. Lograsso, D. L. Schlagel,
              S. L. Budko, V. K. Pecharsky and K. A. Gschneidner, Jr.,
              Phys. Rev. B 71, 214408 (2005).
• Unusual phonon softening in d-phase plutonium,

o        R. J. McQueeney, A. C. Lawson, A. Migliori, T. M. Kelley, B. T. Fultz, M. Ramos, J. C. Lashley, B. Martinez, S. Vogel
Phys. Rev. Lett. 92, 146401 (2004).

·         No role for phonon entropy in the fcc-->fcc volume collapse transition in Ce0.9Th0.1,

o        M. E. Manley, R. J. McQueeney, B. Fultz, T. Swan-Wood, O. Delaire, , E. A Goremychkin, J. C. Cooley, W. L. Hults, J. C. Lashley, R. Osborn, J. L. Smith,
Phys. Rev. B 67, 014103 (2003).

·         In-plane anisotropy and temperature dependence of oxygen phonon modes in YBa₂Cu₃O6.95,

o        J.-H. Chung, T. Egami, R. J. McQueeney, M. Yethiraj, M. Arai, T. Yokoo, Y. Petrov, H. A. Mook, Y. Endoh, S. Tajima,
Phys. Rev. B, 67, 014517 (2003).

·         Vibrational and electronic entropy of a-cerium and g-cerium measured by inelastic neutron scattering,

o        M. E. Manley, R. J. McQueeney, B. Fultz, R. Osborn, G. H. Kwei, P. D. Bogdanoff,
Phys. Rev. B 65, 144111 (2002).

·         Bond-stretching phonon anomalies in stripe-ordered La1.69Sr0.31NiO4,

o        J. M. Tranquada, K. Nakajima, M. Braden, L. Pintschovius, R. J. McQueeney,
Phys. Rev. Lett. 88, 075505 (2002).

·         Mixed lattice and charge states in high-temperature superconductors,

o        R. J. McQueeney, J. L. Sarrao, P. G. Pagliuso, P. W. Stephens, R. Osborn,
Phys. Rev. Lett. 87, 077001 (2001).

·         Unexpected similarity of the dynamic magnetic susceptibility of b-cerium and g-cerium,

o        R. J. McQueeney, M. E. Manley, B. Fultz, G. H. Kwei, R. Osborn, P. Bogdanoff,
Philos. Mag. B 81, 675 (2001).

·         Large harmonic softening of the phonon density-of-states of Uranium,

o        M. E. Manley, B. Fultz, R. J. McQueeney, C. M. Brown, J. L. Hults, J. L. Smith, D. Thoma, R. Osborn, J. L. Robertson,
Phys. Rev. Lett. 86, 3076 (2001).

·         Charge localization and phonon spectra in hole-doped La₂NiO₄,

o        R. J. McQueeney, A. R. Bishop, Ya-sha Yi, Z. G. Yu,
J. Phys.: Condens. Matter 12, L317 (2000).

·         Commensurate dynamic magnetic correlations in La2Cu0.9Li0.1O4,

o        Wei Bao, R. J. McQueeney, R. Heffner, J. L. Sarrao, P. Dai, J. Zarestky,
Phys. Rev. Lett. 84 ,3978 (2000).

·         Phonon densities of states of La2-xSrxNiO4: Evidence for strong electron-lattice coupling,

o        R. J. McQueeney, J. L Sarrao, and R. Osborn
Phys. Rev. B 60, 80 (1999).

·         Anomalous dispersion of LO phonons in La1.85Sr0.15CuO4 at low temperatures,

o        R. J. McQueeney, Y. Petrov, T. Egami, M. Yethiraj, G. Shirane, and Y. Endoh,
Phys. Rev. Lett. 82, 628 (1999).

·         Dynamic radial-distribution function from inelastic neutron scattering,

o        R. J. McQueeney,
Phys. Rev. B 57, 10560 (1998).