Browsing Chemistry Faculty Research, Publications and Presentations by Title

Now showing items 108-127 of 233

  • Lab-scale chemical vapor deposition onto powders 

    113. Jun Wang and M.N Obrovac. Lab-scale Chemical Vapor Deposition onto Powders. AIP Advances, 12 (2022) 075209. doi: https://doi.org/10.1063/5.0095882
    In this paper, a laboratory chemical vapor deposition (CVD) reactor is described, which features an opposing screw rotating fluidized bed. The reactor efficiently concentrates powdered reactants in the reaction zone while ...

  • Li Insertion in Ball Milled Si-Mn Alloys 

    Yidan Cao, J.C. Bennett, R.A. Dunlap and M.N. Obrovac, Li Insertion in Ball Milled Si-Mn Alloys, J. Electrochem. Soc., 165 (2018) A1734-A1740.
    Si1-xMnx (0 ≤ x ≤0.5, x=0.05)alloyswereprepared by ball milling and studied as negative electrode materials in Li cells. These alloys were found to be unique amongtransition metals. When x ≤ 0.35, the alloys are essentially ...

  • Li-ion Battery Negative Electrodes Based on the FexZn1-x Alloy System (Preprint) 

    Published Version: L. MacEachern, R.A. Dunlap and M.N. Obrovac, Li-ion Battery Negative Electrodes Based on the FexZn1−x Alloy System, J. Non-Cryst. Solids, 409 (2015), 183-190. https://doi.org/10.1016/j.jnoncrysol.2014.11.026
    Thin-film Fe-Zn libraries were investigated as negative electrode materials for Li-ion batteries using combinatorial and high-throughput techniques. X-ray diffraction, Mössbauer effect spectroscopy and electron microprobe ...

  • Li15Si4 Formation in Silicon Thin Film Negative Electrodes 

    D.S. Iaboni and M.N. Obrovac, Li15Si4 Formation in Silicon Thin Film Negative Electrodes, J. Electrochem. Soc., 163 (2016), A255-A261.
    The conditions for Li15Si4 formation in Si thin film negative electrodes was studied during charge and discharge cycling in lithium cells. It was found that Li15Si4 formation can be suppressed during cycling of Si thin ...

  • LiF as an Alloy Component or Slurry Additive in Si-Alloy Anodes 

    Robert S. Young, Benjamin Scott, Congxiao Wei and M. N. Obrovac. LiF as an Alloy Component or Slurry Additive in Si-Alloy Anodes. J. Electrochem. Soc. (2020), 167 (16), 160524.
    Electrolyte additives are commonly used to improve electrochemical performance in Li-ion cells. The use of solids as electrolyte additives is far less common. Here, Si40'(FeSi2)(60−x)'(LiF)(x)' (' = volume percent) alloys ...

  • Lithium Insertion in Nanostructured Si1-xTix Alloys 

    Yukun Wang, Simeng Cao, Mariya Kalinina, Lituo Zheng, Linjun Li, Min Zhu and M.N. Obrovac, Lithium Insertion in Nanostructured Si1-xTix Alloys, J. Electrochem. Soc., 164 (2017) A3006-A3010.
    Nanostructured Si1-xTix alloys (0 ≤ x ≤ 0.3) prepared by ball milling were studied as negative electrode materials in Li cells. The alloys comprised a nanocrystalline andamorphousSiphaseandananocrystallineC49TiSi2 phase. ...

  • Low thermal conductivity of the negative thermal expansion material, HfMo2O8 

    Kennedy, Catherine A., Mary Anne White, Angus P. Wilkinson, and Tamas Varga. 2007. "Low thermal conductivity of the negative thermal expansion material, HfMo2O8." Applied Physics Letters 90(15): 151906-151906.
    The thermal conductivity of the cubic polymorph of hafnium molybdate, HfMo2O8, was determined over the temperature range of 2-400 K. The values of thermal conductivity were low (0.64 +/- 0.15 W m(-1) K-1 at T=300 K for a ...

  • Measuring the Geometric Component of the Transition-Probability in a 2-Level System 

    ZWANZIGER, JW, SP RUCKER, and GC CHINGAS. 1991. "Measuring the Geometric Component of the Transition-Probability in a 2-Level System." Physical Review a 43(7): 3232-3240. doi:10.1103/PhysRevA.43.3232
    We describe the measurement of a component of the nonadiabatic transition probability in a two-level system that depends only on the path through parameter space followed by the Hamiltonian, and not on how fast the path ...

  • Mechanical–Structural Investigation of Ion-Exchanged Lithium Silicate Glass using Micro-Raman Spectroscopy 

    Mechanical–Structural Investigation of Ion-Exchanged Lithium Silicate Glass using Micro-Raman Spectroscopy Courtney Calahoo, J. W. Zwanziger, and Ian S. Butler The Journal of Physical Chemistry C 2016 120 (13), 7213-7232 DOI: 10.1021/acs.jpcc.6b01720
    Micro-Raman spectroscopy was used to determine the structural modifications occurring in a simple ion-exchanged glass. The base lithium silicate composition 30Li2O–70SiO2 was studied as it underwent ion exchange, Li+ ↔ K+, ...

  • Microwave-accelerated synthesis of benzyl 3,5-dimethyl-pyrrole-2-carboxylate 

    Regourd, Jasmine, Ian M. Comeau, Cory S. Beshara, and Alison Thompson. 2006. "Microwave-accelerated synthesis of benzyl 3,5-dimethyl-pyrrole-2-carboxylate." Journal of Heterocyclic Chemistry 43(6): 1709-1714.
    Benzyl 3,5-dimethyl-pyrrole-2-carboxylate, a very useful pyrrole in porphyrin and dipyrromethene synthesis, can be synthesized via the Knorr-type reaction, but in low yield. Alternative routes to benzyl 3,5-dimethyl-pyrr ...

  • Microwave-assisted reduction of F-BODIPYs and dipyrrins to generate dipyrromethanes 

    Melanson, J. A., Smithen, D. A., Cameron, T. S., & Thompson, A. (2013). Microwave-assisted reduction of F-BODIPYs and dipyrrins to generate dipyrromethanes. Canadian Journal of Chemistry, 92(8), 688-694. doi: https://doi.org/10.1139/cjc-2013-0341
    The reduction of BODIPYs and dipyrrins to dipyrromethanes, via a reaction involving ethylene glycol and sodium methoxide, is reported. When benzyl alcohol is used in place of ethylene glycol, the addition of 2,4-dinitrop ...

  • Mixed Transition Metal Titanate and Vanadate Negative Electrode Materials for Na-Ion Batteries (Preprint) 

    Published Version: L. Brown, S. Smith and M. N. Obrovac, Mixed Transition Metal Titanate and Vanadate Negative Electrode Materials for Na-Ion Batteries, J. Electrochem. Soc., 162 (2015), A15-A20. https://doi.org/10.1149/2.0171501jes
    Sodium-ion batteries have the potential to be a low cost, sustainable replacement for lithium-ion batteries in large scale energy storage. The lack of practical negative electrode materials limit the development of Na-ion ...

  • Mössbauer and Electrochemical Investigations of Carbon-Rich Fe1-xCx Films (Preprint) 

    Published Version: Xiuyun Zhao, R.J. Sanderson, L. MacEachern, R.A. Dunlap and M.N. Obrovac, Mössbauer and Electrochemical Investigations of Carbon-Rich Fe1-xCxFilms, Electrochim. Acta, 170 (2015), 16-24. https://doi.org/10.1016/j.electacta.2015.04.116
    A thin film binary library of carbon-rich Fe1-xCx (0.47 ≤ x ≤ 0.97) alloys was prepared by combinatorial sputtering of carbon and iron. The sputtered library was characterized by X-ray diffraction and room temperature 57Fe ...

  • Multichannel detection x-ray absorption near edge structures study on the structural characteristics of dendrimer-stabilized CdS quantum dots 

    Reproduced from Zhang, P., SJ Naftel, and TK Sham. 2001. "Multichannel detection x-ray absorption near edge structures study on the structural characteristics of dendrimer-stabilized CdS quantum dots." Journal of Applied Physics 90(6): 2755-2759, with the permission of AIP Publishing.
    No abstract available.

  • Nanoindentation Study of the Surface of Ion-Exchanged Lithium Silicate Glass 

    Nanoindentation Study of the Surface of Ion-Exchanged Lithium Silicate Glass Courtney Calahoo, Xiaofang Zhang, and J. W. Zwanziger The Journal of Physical Chemistry C 2016 120 (10), 5585-5598 DOI: 10.1021/acs.jpcc.6b00733
    Variations in mechanical properties (stiffness and hardness) were measured as a function of case depth in ion-exchange glasses using nanoindentation. A simple silicate composition, 30Li2O–70Si2O, was exchanged (Li+ ↔ K+) ...

  • Nanostructured CdS prepared on porous silicon substrate: Structure, electronic, and optical properties 

    Reproduced from Zhang, P., PS Kim, and TK Sham. 2002. "Nanostructured CdS prepared on porous silicon substrate: Structure, electronic, and optical properties." Journal of Applied Physics 91(9): 6038-6043, with the permission of AIP Publishing.
    No abstract available.

  • The nature of ammonium ion disorder in ammonium tetrafluoroaluminate, NH4AlF4. 

    Reproduced from White, Mary Anne, and Brian D. Wagner. 1985. "The nature of ammonium ion disorder in ammonium tetrafluoroaluminate, NH4AlF4.." Journal of Chemical Physics 83(11): 5844-5848, with the permission of AIP Publishing.
    To clarify previous conflicting reports concerning the existence of an order-disorder phase transition in NH4AlF4 at T ?150 K, the heat capacity of this compd. was measured from T = 15 to 305 K, by adiabatic calorimetry. ...

  • Neutron-Scattering Spectra from the Hindered Rotation of Methane in Methane + Krypton Mixtures Adsorbed on Graphite 

    ALLEN, MP, CB HOVENDEN, RP HUMES, SK METHA, et al. 1985. "Neutron-Scattering Spectra from the Hindered Rotation of Methane in Methane + Krypton Mixtures Adsorbed on Graphite." Faraday discussions 80: 171-182.
    No abstract available.

  • NixSi1-x Alloys Prepared by Mechanical Milling as Negative Electrode Materials for Lithium Ion Batteries 

    NixSi1-x (0 ≤ x ≤ 0.5, x = 0.05) alloys were prepared by ball milling and studied as anode materials for lithium ion batteries. Nanocrystalline Si/NiSi2 phases were formed for x ≤ 0.25. The NiSi phase was observed for ...

  • Non-Abelian Effects in a Quadrupole System Rotating Around 2 Axes 

    ZWANZIGER, JW, M. KOENIG, and A. PINES. 1990. "Non-Abelian Effects in a Quadrupole System Rotating Around 2 Axes." Physical Review a 42(5): 3107-3110. doi:10.1103/PhysRevA.42.3107
    No abstract available.