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 magnetic thin films are prepared by employing an epitaxial thin film growth technique using MgO(110) and (100) single crystal substrates. Uniaxial magneto-crystalline constants (K-u) and Gilbert's damping constants (alpha) of Co, CoCrTa, and CoCrPt thin films are determined by Torque and FMR measurements. (<1(1)over bar 00>) oriented single crystalline and (<11(2)over bar 0>) oriented bicrystalline Co-based thin films are prepared. K-u values of Co, CoCr16Ta4, CoCr15Pt12 thin films are determined to be 4.5 x 10(6), 1.7 x 10(6), 3.3 x 10(6) erg/cc. respectively. The effect of lattice mismatch between the magnetic layer and the Cr alloy underlayer on K-u value of COCr15Pt12 is systematically investigated. The alpha value of the Co and the Co alloy thin films are determined to be ranging between 0.01-0.04. Recording resolution and noise characteristics of the bicrystalline COCr15Pt20 disk medium are also examined as a function of angle from the effective easy axis of the disk medium. (C) 1998 Acta Metallurgica Inc.