Co3Pt合金薄膜之顯微結構與磁性質研究

Abstract

摘要 本研究以直流磁控濺鍍的方式分別鍍製Pt底層於康寧玻璃基板上，並採用具有高磁晶異向性常數之Co3Pt薄膜為磁性記錄層，最後加入Pt保護層，以形成Pt/Co3Pt/Pt/Glass，或是不加入保護層的Co3Pt/Pt/Glass。探討不同底層厚度、Co3Pt磁性記錄層的厚度及退火溫度對Co3Pt薄膜之顯微結構及磁性質的影響。 經XRD及TEM微結構分析結果，Pt底層具有很強的(111)從優取向，經由磊晶作用能誘發Co3Pt磁性層之CoPt (002)從優取向，而Co3Pt薄膜也由水平轉為垂直磁異向性。經VSM磁性質分析結果發現，在退火後不加入Pt保護層之Co3Pt/Pt/Glass比有Pt保護層之Pt/Co3Pt/Pt/Glass薄膜之垂直磁異向性較好。我們將初鍍之Co3Pt (14 nm)/Pt (200 nm) /Glass薄膜經300℃退火後，可得到最佳的磁性質，其Hc⊥ 值為3800 Oe，Ms值為651 emu/cm3及S⊥ 值為0.923，具有應用於垂直磁記錄媒體之潛力。

Abstract Pt underlayer is deposited on the 1737 Corning glass by DC magnetron sputtering, then the Co3Pt film which possess high magnetocrystalline anisotropy is deposited on the Pt layer . In order to avoid oxidation, the Pt capped layer is deposited on the Co3Pt/Pt/Glass film as the protecting layer. In this study, we investigated the effects of Pt underlayer thickness and Co3Pt thickness on the microstructure and magnetic properties of Co3Pt/Pt/Glass film with or without Pt capped layer. From the microstructure analysis of XRD and TEM, it is found that the Pt underlayer possess (111) preferred orientation. The magnetic easy axis of Co3Pt film is transferred from in-plane to out-of-plane as Pt (111) under layer is added, due to the epitaxy between Pt (111) and CoPt (002) films. The M-H loops analysis of Co3Pt/Pt /Glass with or without Pt capped layer show that the Co3Pt/Pt/Glass films without Pt capped layer have much larger magnetic perpendicular anisotropy than that with Pt capped layer. After the Co3Pt (14 nm)/Pt (200 nm)/Glass film without Pt capped layer is annealed at 300℃ for 30 minutes, the Hc⊥, Ms , and S⊥ are 3800 Oe, 651 emu/cm3, and 0.923, respectively. It has significant potential to be applied as the perpendicular magnetic recording medium.