The Recording of Tiny Marks Less Than 100 nm on Magneto-optical Medium Sputtered from RE-TM Alloy Target

摘要

Use of magneto-optical (MO) medium sputtered from an intermetallic compound alloy target has advantages for mass production but may not be suitable for high-density recording due to its poor perpendicular magnetic anisotropy. The relationship between MsHc, the product of saturation magnetization Ms and coercivity Hc, and film microstructure is discussed in this paper; we obtained a' MsHc of 1.3 X 10~6 erg/cm~3 using microcolumnar structure even when the medium was sputtered from an alloy target. By adopting this film for the memory layer in a DWDD system, tiny marks less than 100 nm in size can be reliably written. As a result, high-density recording at 15 Gbit/inch~2 is achieved.