Disorder and superconductivity in Mo/Si multilayers

Abstract

${\mathit{T}}_{\mathit{c}}$ vs ${\mathit{R}}_{\mathrm{\ensuremath{\square}}}$ dependence in thin Mo films and Mo/Si multilayers is simultaneously of three-dimensional (3D) and 2D nature: the main effect of disorder consists in essential increase of ``bulk'' ${\mathit{T}}_{\mathit{c}0}$ which appears to exceed many times ${\mathit{T}}_{\mathit{c}0}$ for pure Mo. The x-ray data enable one to explain the origin of ${\mathit{T}}_{\mathit{c}0}$ enhancement in relatively thick layers. The depression of ${\mathit{T}}_{\mathit{c}}$ with increasing sheet resistance was observed on Mo/Si multilayers in agreement with the theory of superconductivity in disordered 2D metals. It is found that ${\mathit{T}}_{\mathit{c}}$(${\mathit{R}}_{\mathrm{\ensuremath{\square}}}$) dependence for multilayers is quite close to one for single Mo films. \textcopyright{} 1996 The American Physical Society.