Browsing Chemistry Faculty Research, Publications and Presentations by Title
Now showing items 113-132 of 235
-
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 ... -
A mild synthetic route to α-nitroso diaryl pyrroles (Postprint)
A new synthetic method to access α-nitroso pyrroles is presented. This method utilises the nitrosonium salt NOBF4, enabling short reaction times (<10 minutes) and avoiding the harsh acidic conditions usually associated ... -
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 ... -
-
Phase transitions in M(ClO4)2.6H2O (M = magnesium, zinc). Investigations by adiabatic calorimetry and infrared spectroscopy.
IR spectra of Mg(ClO4)2.6H2O at 10 K indicate a complex structure contg. at least 16 distinct types of H2O protons. At 107.9 K this structure transforms sharply to a much simpler disordered form (?Strans = 7.754 J K-1 ...