Publication Date


Advisor(s) - Committee Chair

William Buckman, N.F. Six, F.M. Carter

Degree Program

Department of Physics and Astronomy

Degree Type

Master of Science


This thesis describes the results and analysis of Seebeck coefficient and electrical conductivity measurements on "activated", molybdenum-oxide, thin film hydrogensensing elements. The work was undertaken in an effort to produce data that would be useful in obtaining an understanding of the electronic processes which cause large electrical conductivity changes in molybdenum-oxide upon exposure to small concentrations of hydrogen in air. The results are analyzed using a simple band model of a semiconductor. This model is shown to give reasonable results at high temperatures; however, a departure from the usual .! model is required in order to explain the results at lower temperatures. Evidence is presented concerning the basic nature of the charge carriers, and a possible defect model is suggested. Similar measurements were also performed on single crystals, and the results are shown to be in reasonable agreement with those obtained on thin film samples.


Engineering Physics | Physical Sciences and Mathematics | Physics