Dependence of the properties of Co/Ti multilayered films on the ferromagnetic sublayer thickness

Co/Ti multilayered films (MLF) (d(Co) = 1,2, 2.5, 3.3 and 4 nm, d(Ti) = 2.5 nm) were prepared at room temperature by a computer-controlled double-pair -target face-to-face sputtering technique. The optical conductivity (OC) an d the equatorial Kerr effect (EKE) were measured at room temperature in a s pectral range of 1-5 eV as well as the magnetic properties. In addition, th e theoretical simulations for the EKE and OC spectra were carried out by so lving exactly a multireflection problem with a matrix method, assuming eith er sharp interfaces or mixed (alloyed) interfaces of various thickness betw een sublayers. The agreement between the experimental and simulated OC spec tra was improved when intermixed layers of 0.6 nm thick were assumed betwee n the sublayers. The atomic and magnetic structures of the Co/Ti MLF with a CO sublayer thickness above and below a critical value were also investiga ted, The significant difference in the experimental and simulated EKE spect ra below the critical thickness was analyzed in terms of a polycrystalline- to-nanocrystalline (or amorphous) structural transition of Co sublayers. (C ) 1999 Elsevier Science S.A. All rights reserved.