Solid state amorphisation in magnetic multilayers:: the interface structure and the electrical transport properties

The structure and electrical conductivity properties of the R.F. sputtered Fe/Zr and Fe/Ti multilayers with ultrathin layer thicknesses, in as-deposited states, have been studied using X-ray diffraction, low-angle X-ray and neutron reflectometry, conversion electron Mossbauer spectroscopy (CEMS). resistivity and magnetoresistivity measurements. The thickness ratio (beta = d(Fe)/d(Zr) and d(Fe)/d(Ti)) of analysed multilayers was 0.5 and 1, the values of the bilayer thickness (lambda = d(Fe) + d(Ti,Zr)) was varied from 9 Angstrom to 600 Angstrom, maintaining constant the total thickness of the samples by controlling the number of bilayers, The results obtained from CEM-spectroscopy and X-ray diffraction show that Fe layers of the thickness below 20 Angstrom are alloyed forming an amorphous phase during deposition. This amorphous phase is distributed in the plant: between the crystalline sublayers as well as in the grain boundaries according with the proposed model of the interpretation of the electrical conductivity as a function of the bilayer thickness (lambda). (C) 1999 Elsevier Science Ltd. All rights reserved.