Giant changes in magnetic and magnetoresistive properties of CoFe/Cu multilayers at subnanosized variations in the thickness of the chromium buffer layer

The article discusses the magnetic and magnetoresistive properties of the [Co90Fe10/Cu]n multilayers prepared by magnetron sputtering as a function of the type of the substrate and the material and thickness of a buffer layer (Co90Fe10, Cu, Cr, Fe). The multilayers with a chromium buffer layer exhibit a sharp transition from low-coercive to high-coercive state at low variations in the thickness of the chromium layer (from 15 to 20 Å). It has been demonstrated that the revealed sudden change in the hysteresis properties of the multilayers with a Cr buffer layer is accompanied by structural changes in the Cu and Co90Fe10 layers, characterized by the disappearance of the 〈111〉 texture at tCr > 20 Å. It has been found that the most efficient buffer layer, which at room temperature ensures a threefold increase in the magnetoresistance at a minimum increase in hysteresis, is the Co90Fe10 (15 Å) layer. It has been established that the substrate type ((100)Si, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(10\bar 12)$$\end{document} Al2O3, glass) does not exert a significant effect on the magnetoresistive properties of the multilayers studied.