Magnetic Properties and Domain Structure of SmCo5 Perpendicular Magnetization Films Prepared by Using a UHV Sputtering System

Abstract

The effects of the thicknesses of a Cu/Ti underlayer and a Sm-Co layer on the magnetic properties and domain structure of SmCo5 perpendicular magnetization films prepared by using an ultra-high-vacuum sputtering system were investigated. By adjusting the thicknesses of both the Cu/Ti underlayer and the Sm-Co layer, the coercivity was controlled to be a moderate value, allowing the films to be used in magnetic recording media while maintaining a squareness ratio of unity. As the Sm-Co layer thickness was reduced, the magnetic cluster size decreased and the magnetization reversal process varied from wall motion mode to a rotation mode. It is suggested that the Cu-rich region in the initial growth stage of the Sm-Co layer functions as the pinning site of the magnetic domain wall and plays an important role in controlling the magnetic domain structure.

Sputter-Deposited SmCo5 Thin Films with Perpendicular Magnetic Anisotropy for High Density Magnetic Recording Media

“…3 (a). We previously pointed out that a large amount of Cu around the interface was a key to obtaining high perpendicular magnetic anisotropy (19,21). Referring to the previous studies on the Sm-Co permanent magnets (24)(25)(26)(27)(28)(29), we consider that the Cu atoms around the interface stabilize the SmCo 5 phase and promote its crystallization.…”

“…ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.112.200.107 Downloaded on 2015-07-10 to IP anisotropy constant as high as 1.5 × 10 7 erg/cm 3 was obtained (19). The minimal stable grain diameter of this medium is estimated to be 5.1 nm from the anisotropy constant.…”

Developing SmCo5 perpendicular magnetization thin films for magnetic recording media

“…Furthermore, the Hc values were found to be controllable in the range from several kilo Oersted to upwards of ten kilo Oersted by adjusting the thicknesses of both the Cu/Ti underlayer and the Sm-Co layer 26) . Figures 7 and 8 In addition, the read-write characteristics of SmCo5 thin film as a perpendicular magnetic recording medium have been evaluated on a preliminary level 27) .…”

“…These problems were solved by using a UHV sputtering system and by modifying the layer configuration and deposition conditions 26) . Figure 6 shows the relationship between the SQR for the films prepared using the UHV sputtering system and the base pressure in the sputtering chamber before the films were deposited.…”

Magnetic Thin Films for Perpendicular Magnetic Recording Systems

“…However, an SmCo 5 thin film exhibiting distinct perpendicular magnetic anisotropy had not been prepared, although the film with in-plane anisotropy is relatively easy to prepare, for instance, by using a Cr underlayer [35][36][37][38][39]. Recently, we succeeded in developing sputter-deposited SmCo 5 thin films with very high perpendicular magnetic anisotropy [40][41][42][43][44][45]; it will be stated in detail in this section.…”