Magnetic Properties and Columnar Structure for CoPt Alloy Granular Media With Grain Boundary Oxides of Various Melting Points

Investigation of the effect of the melting point (Tm) of various single oxides on the columnar growth and generation of the nucleation site for CoPt granular media deposited at room temperature were conducted. When oxide with T_m from 1857 °C to 2410 °C is added to the granular media, thickness of the heteroepitaxial growth of the magnetic grains on the Ru underlayer (columnar structure) decreases from 13 to 5.5 nm. The employment of oxide with T_m of the range from 450 °C to 2410 °C to the granular media will lead to the reduction of grain size from 5.6 to 3.0 nm, due to the suppression of the lateral grain growth by the high T_m oxide.