1999 Fiscal Year Final Research Report Summary
Preparation of Cobalt-Platinum Alloy Films with Hexagonal Close-Packed Structure for Perpendicular Magnetic Recording Application
| Project/Area Number |
10650309
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Electronic materials/Electric materials
|
|---|
| Research Institution | Mie University |
|---|
Principal Investigator |
SHIOMI Shigeru Mie University, Department of Electrical and Electronic Engineering, Associate Professor, 工学部, 助教授 (00115578)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Keywords | magnetic thin film / perpendicular anisotropy / coercivity / hexagonal structure / cobalt-platinum Alloy / perpendicular magnetic recording / sputtering |
|---|
| Research Abstract |
Highly (111) -oriented Pt underlayers were prepared by sputtering them on mica substrates. Then, Co-Pt alloy films with different Pt contents were sputtered on them. The crystal structure of the Co-Pt alloy films thus prepared were analyzed by the X-ray pole figure measurements. It was revealed that the Co-Pt alloy films with Pt contents larger than 60 % take the (111)-oriented face-centered cubic (fcc) structure, whereas those with pt contents less than 40 % take the (0001)-oriented hexagonal close-packed (hcp) structure. Co-Pt alloy films were also sputtered on highly (100)-oriented fcc structure irrespective of the Pt underlayers prepared on (100)-oriented NaCl substrates. They were found to take the (100)-oriented fcc structure irrespective of the Pt content. The perpendicular magnetic anisotropy of the Co-Pt alloy films strongly depends on the crystal structure. That is, the Co-Pt alloy films with (0001)-oriented hcp structure show much higher perpendicular anisotropy than those with (111)- or (100)- oriented fcc structure. The Co-Pt alloy films with Pt contents around 30 % possess the easy magnetization direction perpendicular to the film plane. The crystal structure of Co-Pt alloy films depends on the substrate temperature during the deposition, changing from (0001)-oriented hcp to (111)-oriented fcc structure when the temperature exceeds 200℃. This change from hcp to fcc structure is accomplished by the Pt underlayer thickness, becoming nearly constant for the thickness lager than 200 nm. Co-Pt alloy films with (0001)-oriented hcp structure can also be prepared on Au or Cu underlayers provided that their (111)-orientation is high enough. A small amount of Cr enhanced the perpendicular anisotropy decrease slightly. The addition of Al results in a great reduction of the perpendicular anisotropy.
|
Research Products
(2 results)
