Raymond W. Mires

Magnetic Susceptibilities of Metallic V2O3 Single Crystals

The magnetic susceptibilities of single‐crystal V2O3 have been measured by the Faraday method along and perpendicular to the trigonal axis between 300° and 700°K. Both χ‖ and χ⊥ have a high‐temperature transition, as was expected, which occurs over a range of temperature from 450° to 550°K. An approximate fit of the data can be obtained with a Curie‐Weiss law including a temperature‐independent term with one set of parameters below 400°K and a different set above 550°K. It is found that the reciprocal susceptibility curve over the entire temperature range is at least cubic in T, indicating a rather complicated temperature dependence for the density of states function in the band approximation.

The dynamic Jahn–Teller effect applied to the temperature-dependent paramagnetic susceptibilities of Ti3+:Al2O3

The dynamic Jahn–Teller effect has been used in the analysis of the temperature-dependent paramagnetic susceptibilities of Ti3+:Al2O3. Two important changes have been made from the original analysis: (1) Parameters as determined from the dynamic Jahn–Teller effect are incorporated, and (2) All Van Vleck susceptibilities have been forced to sum to zero as required by quantum theory. The results of the analysis show that χ∥ contains a constant term of the order 1.22×10−8 emu/g that does not arise from Ti3+ singles. The data over the temperature range 18 to 100 K indicate that g∥1=2.54, a value 25% larger than that determined from the infrared Zeeman effect. It is possible to determine the perpendicular Van Vleck susceptibility for the ground state which is governed by the magnetic interaction of the lowest two energy levels with a substantial Jahn–Teller contribution. Finally, the suppression of the susceptibilities below 4.12 K can be modeled by a factor for the removal of singles from the susceptibilities...

MAGNETIC IDENTIFICATION OF HEADLIGHT GLASS

Magnetic susceptibility measurements over the temperature range 4 to 300K have been used to identify and distinguish among various samples of headlight glass. With a few exceptions, it is found that the technique can be useful in such applications and that improvements in accuracy, which are possible, would even eliminate these exceptions. The method is also applicable to the identification of other types of sample of forensic sceince interest such as soils, window glass, and metals.