METAL-INSULATOR-TRANSITION IN UNCOMPENSATED SIP IN THE PRESENCE OF A MAGNETIC-FIELD

Citation
M. Hornung et al., METAL-INSULATOR-TRANSITION IN UNCOMPENSATED SIP IN THE PRESENCE OF A MAGNETIC-FIELD, Europhysics letters, 28(1), 1994, pp. 43-47
Citations number
23
Categorie Soggetti
Physics
Journal title
ISSN journal
02955075
Volume
28
Issue
1
Year of publication
1994
Pages
43 - 47
Database
ISI
SICI code
0295-5075(1994)28:1<43:MIUSIT>2.0.ZU;2-R
Abstract
We report on detailed measurements of the electrical conductivity sigm a(T) in uncompensated Si:P in a magnetic field B of 6T between 30 mK a nd 1K. The approximate relation sigma(T) = sigma(0) + m(B) square-root T allows a reliable extrapolation of sigma(0). The critical behaviour sigma(0) approximately (N - N(c))mu' close to the critical P concentr ation N(c) yields a critical exponent mu' almost-equal-to 1.3, with a tendency to smaller values at a crossover concentration which is close to the concentration where m(B) changes strongly. The implications fo r the previously proposed solution to the exponent puzzle for B = 0 ar e discussed.