Magnetic Properties and Intergranular Interactions of Fe-Pt-Mn Thin Films

Fe-Pt-Mn thin films were deposited on quartz substrates and post annealed at a temperature range of 25-800 °C. The studied compositions include Fe_(50)Pt_(43)Mn_7, Fe_(50)Pt_(46)Mn_4, and Fe_(40)Pt_(56)Mn_4. X-ray diffraction data indicate that the Mn dissolving in the FePt lattice tends to stabilize the disordered fcc-FePt phase. The ordering transformation temperature was thus increased by about 150 °C. Besides, Mn also shows an effect of microstructure refining by 40%. L1_0 ordering can be enhanced by alloying a high concentration of 56 at% Pt. The higher degree of ordering enhances the coercivity value. δM analysis indicate that larger grain sizes and higher ordering significantly reduce the intergranular interactions of the Fe-Pt-Mn films.

關鍵字

Fept films ； Fuse quartz substrates ； Mn-doping ； Magnetic properties ； Microstructure

並列摘要

本文以高真空磁控濺鍍系統製備Fe-Pt-Mn薄膜並研究其磁性及晶粒間交互作用。研究成份包含Fe_(50)Pt_(43)Mn_7, Fe_(50)Pt_(46)Mn_4, 及Fe_(40)Pt_(56)Mn_4等。結構分析結果顯示Mn溶進FePt中穩定了非序化fcc-FePt相。序化溫度約提高了150℃。另一方面，Mn具有微結構細化效應。L1_0序化可被合金化高Pt含量(56 at%)所提高。較高之序化度提高了矯頑磁力。δM分析指出較大的晶粒與較高序化度可有效地降低Fe-Pt-Mn膜中晶粒間之交互作用。