MICROSTRUCTURES AND BASIC MAGNETIC-PROPERTIES OF CO-BASED EPITAXIAL MAGNETIC THIN-FILMS

To investigate the basic magnetic and recording characteristics of Co and Go-based alloy thin films, single crystalline and bicrystalline ma gnetic thin films are prepared by employing an epitaxial thin film gro wth technique using MgO(110) and (100) single crystal substrates. Unia xial magneto-crystalline constants (K-u) and Gilbert's damping constan ts (alpha) of Co, CoCrTa, and CoCrPt thin films are determined by Torq ue and FMR measurements. (<1(1)over bar 00>) oriented single crystalli ne and (<11(2)over bar 0>) oriented bicrystalline Co-based thin films are prepared. K-u values of Co, CoCr16Ta4, CoCr15Pt12 thin films are d etermined to be 4.5 x 10(6), 1.7 x 10(6), 3.3 x 10(6) erg/cc. respecti vely. The effect of lattice mismatch between the magnetic layer and th e Cr alloy underlayer on K-u value of COCr15Pt12 is systematically inv estigated. The alpha value of the Co and the Co alloy thin films are d etermined to be ranging between 0.01-0.04. Recording resolution and no ise characteristics of the bicrystalline COCr15Pt20 disk medium are al so examined as a function of angle from the effective easy axis of the disk medium. (C) 1998 Acta Metallurgica Inc.