Browsing Chemistry Faculty Research, Publications and Presentations by Title
Now showing items 108-127 of 234
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Lab-scale chemical vapor deposition onto powders
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
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)
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
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
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
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
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
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
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
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
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)
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)
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 ... -
Nanoindentation Study of the Surface of Ion-Exchanged Lithium Silicate Glass
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+) ... -
The nature of ammonium ion disorder in ammonium tetrafluoroaluminate, NH4AlF4.
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. ... -
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 ... -