鉑鐵合金與磁性薄膜介面的磁性研究

Investigation of Magnetism for the Magnetic Thin Films on Fept (111) Surface Alloy

陳耀榮(Yao-Jung Chen) ； 蔡志申(Jyh-Shen Tsay)

《台北海洋技術學院學報》 6卷2期 (2015/03) Pp. 18-27

摘要

在超高真空腔內蒸鍍兩原子厚度（2ML）的超薄鐵膜在Pt（111）表面上，使用表面磁光柯爾效應儀（SMOK E）探測其磁性和退火溫度的關係，室溫下利用小磁場（小於1000 Oe）可以測得磁化易軸位於平行表面方向（Longitudinal)。2ML Fe/Pt（111）經退火效應後在室溫測量磁滯訊號，發現只更在Longitudinal 方向更值，當退火溫度達到650K~700K時，其Longitudinal 方向的矯頑力（Hc）顯著的增強至4.5倍，而垂直表面方向（Polar）的磁化曲線並無明顯的變化。再蒸鍍2 ML Co在2 ML Fe/Pt（111）樣品上並探測其磁性變化，隨著2 ML Co原子的覆蓋，其Longitudinal 方向的MOKE在柯爾訊號和矯頑磁場皆更增強的現象，但Polar方向的MOKE依然無明顯的變化。將2 ML Co/2 ML Fe/Pt（111）樣品進行退火處理後，發現Longitudinal方向矯頑力增強的溫度從650 K下降為500 K，且在700 K時的Hc從410 Oe增強至550 Oe，而Polar方向的磁化曲線並無明顯的改變。磁性薄膜磁性的變化除了受不同原子層的介面效應所影響，也會隨溫度增加時形成合金，而產生顯著的改變。

關鍵字

鐵 ； 鈷 ； 表面磁光柯爾效應 ； 表面磁異向性能

並列摘要

The experiment is planned in the ultra high vacuum system (below 5×10-10 mbar), the 2 atom layers (monolayers, ML) Fe films are steamed and plated on a Pt (111) surface. The measurement of SMOKE (surface magneto-optic Kerr effect). It is influenced by the extra magnetic field to survey its magnetic relation with annealed temperature. By the small magnetic field (less than 1000 Oe), the easy magnetization axis is in the parallel surface direction (Longitudinal) at room temperature. To measure the hysteresis signal of 2 ML Fe/Pt (111) at the room temperature, only in longitudinal direction the signal is found. When the annealed temperature reaches 650 K-700 K, the coercivity (Hc) on the longitudinal direction is apparent enhancement to 4.5 times, but the change of vertical surface direction (Polar) magnetize curve is not obvious. By steaming and plating 2 ML Co on 2 ML Fe/Pt(111) and measuring its magnetic change on the sample, the L-MOKE all have enhanced phenomena with the Kerr's signal and the coercivity, but P-MOKE does not still have obvious change. The start temperature of coercivity on the longitudinal direction to enhance drops to 500 K from 650 K, and the Hc strengthens from 410 Oe to 550 Oe at 700K, but there is not obvious change in the magnetization curve of Polar direction. The magnetic change of the magnetic thin films is not only due to interface effects of different atomic layers, but also the alloy form while the temperature is increasing.

並列關鍵字

Iron ； Cobalt ； SMOKE ； Surface-anisotropy energy

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