The effect of applied uniaxial stresses on the optical absorption of F centers in alkali halides

The method of moments is used to analyze the effect of applied uniaxial stresses on the optical absorption of alkali halides containing F centers. By measuring the first moment change of the F band due to uniaxial stresses applied in (100) and (1l0) directions,' the coupling of the F center excited state to lattice distortions of tetragonal and trigonal symmetry is evaluated. By measuring the third moment change due to the same ~pplied stresses, the separate contributions to the second moment of the F band of dynamic lattice distortions of tetragonal, trigonal, and breathing symmetries are evaluated. I Measurements of the zeroth moment change due to applied .stresses allow evaluation of the validity of the Condon approximation. Calculations based on three simple models of the K band are compared with the results of a measurement of the change in zeroth and-first moments of the K band produced by applied uniaxial stresses. The temperature dependence of the zeroth and first moments of the K band is calculated for the same three models. The results indicate that the K band is .. not .. due to transitions to a state of even parity. Brief measurements of the stress-induced dichroism in the Vl' R, and M band regions are reported.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Schnatterly, Stephen Eugene

Contributors dc:contributor

• Compton, W.D.

• applied uniaxial stresses
• optical absorption
• f centers
• alkali halides
• F band
• lattice distortions
• tetragonal symmetry
• trigonal symmetry

Statement dc:rights

• 1965 Stephen Eugene Schnatterly

Language dc:language

en

Identifier

6188880

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/23981