Large Area Nb Nanolayers with Advanced Superconducting Properties as a Base for Superconducting Spintronics

Abstract

High quality Nb nanoscale films of large area (7 × 80 mm2) and constant thickness were deposited by DC-magnetron sputtering in commercial “Leybold Z400” vacuum system. Homogeneity and proper thickness of the Nb layer provided by the target-holder movement during the DC sputtering using specially constructed arrangement based on controllable DC motor with a gear. Rutherford backscattering spectrometry was used for precise thickness measurements. The increase of superconducting critical temperature (>1.5 K for films with comparable thickness) and of superconducting coherent length (up to 30–35%) in comparison with films prepared by common technique is reported.