Dr. Marjorie Langell, Charles Bessey Professor
University of Nebraska-Lincoln
629 Hamilton Hall
Lincoln, Nebraska 68588-0304
Professor Langell's research focuses on the surface properties of transition metal oxides (TMOs) and TMO nanoparticle systems. TMO materials are studied over a range of crystallite size and morphology to elucidate the effect of particle size and composition on structural, electronic, magnetic and chemical properties as the TMO system is varied from macroscopic to nanoparticle dimensions.
Rocksalt (MO, M = MnO, FeO, NiO, CoO), spinel (M3O4, M = Mn, Fe, Ni, Co) and corundum (M2O3, M = Mn, Fe) 3d TMOs are emphasized in our single crystal studies. Single crystal substrates provide well-defined surface sites for gas adsorption and heterogeneous catalysis. One aspect of this work creates vicinally-cut "stepped" TMO surfaces to model low-coordination defects and other nanostructured morphologies. TMO nanoparticle synthesis and characterization are also presently under investigation in our group. Nanoparticle systems are studied both as single-metal component TMOs and as solid solutions of the form MxM'1-xO, involving two or more metals in a single-phase nanoparticle. The compositional variability provides an additional dimension in fabrication for studying nanoparticle behavior and allows us to tailor their chemical and magnetic properties to specific materials applications.
TMOs are ubiquitous in nature and their properties are relevant to a range of materials properties. These include catalysis, environmental chemistry and chemical remediation, magnetism and a number of device applications. The surface properties are studied in house by a variety of techniques, including high resolution electron energy loss spectroscopy (HREELS), photoemission (XPS, UPS), low energy electron diffraction (LEED), thermal desorption mass spectrometry (TDS), secondary ion mass spectrometry (SIMS) and Auger electron spectroscopy (AES). Bulk structural characterization is performed with x-ray diffraction (XRD), transition electron microscopy (TEM) and x-ray absorption fine structure (XAFS). Magnetic characteristics are probed with vibrating magnetometry (VMS) and SQUID.
M.A. Peck and M.A. Langell, "Comparison of Nano-scaled and Bulk NiO Structural and Environmental Characteristics by XRD, XAFS and XPS", Chemistry of Materials, submitted.
M.A. Peck, M. D. Allison, Y. Huh, R. Skomski, R. Zhang, P. Kharel, D. J. Sellmyer, and M. A. Langell, "Magnetic Properties of NiO and (Ni, Zn)O Nanoclusters", Journal of Applied Physics, 109, 07B518/1-4 (2011).
Crystallographic and electronic structure of rocksalt CuxNi1-xO solid solutions. Voelker, Jesse N.; Gaskell, Karen J.; Langell, Marjorie A.. Abstracts of Papers, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010 (2010),
Particle size effects in ZnO/NiO mixed-metal oxides. Peck, Matthea A.; Gaskell, Karen J.; Langell, Marjorie A.. Abstracts of Papers, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010 (2010),
N. Hong, M Langell and S Adenwalla, “N-doping of Semiconducting Boron Carbide”, Phys. Rev. B, 107(2), 024513/1-7 (2010).
M.A. Langell, E.B. Kadossov, H. Boparai and P.J. Shea, “Effect of Dithionite on the Surface Composition of Iron-Containing Aquifer Sediment,” Surface and Interface Analysis, 41(12/13), 941-950 (2009).
S.C. Petitto, E.M. Marsh, G.A. Carson and M.A. Langell, “Cobalt Oxide Surface Chemistry: the Interaction of CoO(100), Co3O4(110) and Co3O4(111) with Oxygen and Water”, J. Molecular Catal. A, 281, 49-58 (2008).
K.J. Gaskell, A. Starace and M.A. Langell., “ZnxNi1-xO Mixed-Metal Oxides by XPS and Auger”, Surf. Sci. Spectra, 14, 79-102 (2008, Vol.. Date 2007).
K.J. Gaskell,, A. Starace and M.A. Langell., “ZnxNi1-xO Mixed-Metal Oxides by AES”, Surf. Sci. Spectra, 14, 68-78 (2008, vol. date 2007).
Evgueni B. Kadossov and Marjorie A. Langell, “Effect of surrounding point charges on the density functional Calculations of NiXOx clusters (x=4-12)”, J. Computational Chem., 8(7), 1240-1251 (2007).
Anthony W. Moses, Harry G. Garcia Flores, Jong-Gyu Kim and Marjorie A. Langell, “Surface Properties of LiCoO2, LiNiO2 and LiNi1-xCoxO2”, Appl. Surf. Sci, 253(10), 4782-4791 (2007).
K.J. Gaskell, A. Starace and M.A.Langell,“ZnxNi1-xO Rocksalt Oxide Surfaces: Novel Environment for Zn2+ and Its Effect on the NiO Band Structure”, J. Phys. Chem. C, 111(37), 13912-13921 (2007).
S.C. Petitto, E.M. Malone, and M.A. Langell, “Adsorption of Bromobenzene on Periodically-Stepped NiO(100), Journal of Physical Chemistry B, 110(3),1309-1318 (2006).
S.C. Petitto, C.L. Berrie, and M.A. Langell, “Novel Mesoscale Defect Structure on NiO(100) Surfaces by Atomic Force Microscopy”, Surf. Sci. Lett., 600(17), 229-235 (2006).
E. M. Malone, S. C.Pettito and M. A. Langell, “Fuchs-Kliewer Phonon Spectrum of Co3O4(110) Single Crystal Surfaces by High Resolution Electron Energy Loss Spectroscopy”, Solid State Comm. 130 9, 571-575 (2004).
D. L. Pugmire, C. M. Woodbridge, N. M. Boag and M. A. Langell, “Adsorption and Decomposition of Nickelocene on Ag(100): A HREELS and TPD Study”, Surface Sci. 472, 155-171 (2001).
M. A. Langell, J. G. Kim, D. L. Pugmire and W. McCarroll, “The Nature of Oxygen at Rocksalt and Spinel Oxide Surfaces”, J. Vac. Sci. Technol. 19(4), 1977-1982 (2001).
M. A. Langell, F. Gevrey and M.W. Nydegger, “Surface Composition of MnxCo1-xO Solid Solutions by X -ray Photoelectron and Auger Spectroscopies”, Appl. Surface Sci. 153, 114-127 (2000).
· Cynthia M. Woodbridge, Ph.D. 2002, Assistant Professor of Chemistry, Hillsdale College, Hillsday, MI.
· David L. Pugmire, Ph.D. 2000, Staff Scientist, Los Alamos National Laboratory, Los Alamos, NM.
· Michael W. Nydegger, MS. 1999, Lecturer, Butler Community College, Butler, KS.