Transport mechanisms in infinite layer phase compounds grown by molecular beam epitaxy

Abstract

Thin films of infinite layer compounds were prepared by molecular beam epitaxy. Defect layers were incorporated into the structure in order to dope the infinite layer phase. Hole type doping is usually observed. Resistivity measurements show that the conduction mechanisms change gradually with increasing doping level, from activational type to variable range hopping (or a mechanism governed by the Coulomb interaction between localized electrons) and then further to a mechanism related to weak localization which can be described by Δρ=T−S, where the exponent S ranges from 0.5 to 1.5.