The DX centre
T.N. Morgan
Semiconductor Science and Technology
A reexamination is made of previous resistivity data of the TiO0.80-1.23 metallic oxide system, in which very large positive and negative temperature coefficients of resistivity α are observed. TiO0.80-1.23 samples contain a large number of stoichiometric vacancies which can be thermally ordered and disordered, drastically changing the residual resistivity, without seriously affecting the superconducting Tc. Fitting the results to the two-level model shows that any resistivity due to the two-level system must operate in parallel with the normal electron-phonon interactions. A phenomenological formula, based on the ideas of incipient localization in very-high-resistivity materials, is introduced. This formula fits all the data for the TiO0.80-1.23 system in a semiquantitative way. It also predicts that a zero α (the Mooij criterion) occurs when the elastic mean free path and the weak localization coherence length are approximately equal. © 1982 The American Physical Society.
T.N. Morgan
Semiconductor Science and Technology
Oliver Schilter, Alain Vaucher, et al.
Digital Discovery
P. Martensson, R.M. Feenstra
Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
S. Cohen, J.C. Liu, et al.
MRS Spring Meeting 1999