Cr90Ru10/Fe55Pt45及Cr90Ru10/Fe55Pt45/Cr90Ru10薄膜之磁性質及顯微結構研究
Study of the Magnetic Properties and Microstructures of Cr90Ru10/Fe55Pt45 and Cr90Ru10/Fe55Pt45/Cr90Ru10 Thin Films
Date Issued
2005
Date
2005
Author(s)
Lee, Chang-Tai
DOI
zh-TW
Abstract
Cr90Ru10 underlayer is deposited on natural-oxidized Si substrate by dc magnetron sputtering, then deposits high magnetocrystalline anisotropy Fe55Pt45 films as magnetic layer on the Cr90Ru10 underlayer. A Cr90Ru10 top layer is deposited on the Fe55Pt45 layer. The effects of Cr90Ru10 underlayer, Cr90Ru10 top layer and process parameters on the microstructure, magnetic properties, and easy axis of Cr90Ru10/Fe55Pt45 and Cr90Ru10/Fe55Pt45 /Cr90Ru10 multilayer films are investigated.
X-ray diffraction pattern and TEM analyses indicate that the (002) preferred orientation of Cr90Ru10 underlayer can be promoted by varying substrate temperature and sputtering power. Cr90Ru10（002） preferred orientation can be achieved by using dc power of 50W with substrate temperatures in the range of 300℃ to 450℃.
Magnetic properties of the Cr90Ru10（35 nm）/Fe55Pt45（25 nm） bilayer films varie with sputtering power of Fe55Pt45 magnetic layer. When the substrate temperature is fixed at 350℃ and sputtering power was set in the range of 10 to 20W, the in-plane coercivity Hc// of Cr90Ru10（35 nm）/Fe55Pt45（25 nm） bilayer films is above 2000 Oe. However, the Hc// of Cr90Ru10（35 nm）/Fe55Pt45（25 nm） bilayer films is lower than 1500 Oe as the sputtering power is higher than 30W.
As the substrate temperature is fixed at 350℃, the Hc// of Cr90Ru10（35 nm）/Fe55Pt45（15 nm） bilayer film is 1815 Oe. As the FePt magnetic layer thickness increases to 40 nm, the Hc// increases to 3219 Oe. Average grain size of the Fe55Pt45 magnetic layer in the Cr90Ru10（35 nm）/Fe55Pt45（40 nm） bilayer film is about 11 nm. Its in-plane remnant magnetization M// is 675 emu/cm3, and in-plane squareness S// is about 0.91. It has revealed its prominent potential to be applied as longitudinal magnetic recording media for high-density recording.
An in-situ ordered Fe55Pt45 film in the Cr90Ru10（15 nm）/Fe55Pt45（25 nm） bilayer film is obtained at the substrate temperature of 300℃ and its Hc// is 1509Oe. When the substrate temperature increases to 325℃, the Hc// of Cr90Ru10（15 nm）/Fe55Pt45（25 nm） bilayer film is increased to 2247 Oe. Average grain size of the Fe55Pt45 magnetic layer in this film is about 7.91 nm. Its M// is 671 emu/cm3, and S// is about 0.90.
When the thickness of Cr90Ru10 underlayer is in the range of 10-100 nm, the Hc// of the Cr90Ru10/Fe55Pt45（25 nm） bilayer film increases with increasing Cr90Ru10 thickness as the substrate temperature is 350℃. The Hc// of Cr90Ru10（15 nm）/Fe55Pt45（25 nm） bilayer film is 2131 Oe. As the Cr90Ru10 thickness increases to 50 nm, the Hc// increases to 4000 Oe. Average grain size of the Fe55Pt45 magnetic layer in the Cr90Ru10（50 nm）/Fe55Pt45（40 nm）bilayer film is about 10.67 nm.
Average grain size of the Cr90Ru10（15 nm）/Fe55Pt45（25 nm） bilayer film is about 8.60 nm and its Hc// is 2131 Oe. After introducing 4 nm Cr90Ru10 top layer, the Hc// of Cr90Ru10（15 nm）/Fe55Pt45（25 nm）/Cr90Ru10（4 nm）multilayer increases to 2300 Oe and its average grain size is reduced to 7.65 nm. The addition of 4 nm Cr90Ru10 top layer on the Cr90Ru10（15 nm）/Fe55Pt45（25 nm）bilayer films increases Hc// and reduces the average grain size of Fe55Pt45 magnetic layer.
Subjects
鐵鉑
鉻
磁記錄
水平磁性質
FePt
Cr
magnetic recording
perpendicular magnetic properties
Type
thesis
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