VERTICAL MAGNETIC RECORDING MEDIUM AND ITS MANUFACTURING METHOD.

摘要

A vertical magnetic recording medium comprising a magnetic layer having the constitution in which two ferromagnetic metallic thin films made of columnar crystal particles are laminated, wherein the angle THETA between the average growth direction of columnar crystal particles and the substrate normal is equal to or larger than 45 DEG at the lower layer and equal to or smaller than 30 DEG at the upper layer, and the average maximum diameter of the lower-layer columnar crystal particles is larger than that of the upper-layer columnar crystal particles. The apparatus preferable for vapor deposition of the magnetic layer has the constitution shown in the selected figure. Because the magnetic flux of the upper layer escapes to the lower layer, it is prevented that a closed loop of magnetic flux is formed in upper-layer columnar crystal particles. Also because the lower layer is magnetized, it contributes to improvement of reproduction output.