本論文主要在研究多層膜之垂直異向性結構組成及其介面特質,本實驗多層膜選取的材料為鐵磁性的鈷(Co)以及貴重金屬的鉑(Pt),並利用濺鍍(Sputtering)系統來製作(鈷/鉑)多層膜樣品,最初的實驗為尋找(鈷/鉑)多層膜結構組成最佳垂直易性發生之條件,所以分別變化鐵磁層鈷之厚度、一般金屬層鉑之厚度、(鈷/鉑)雙層層數及緩衝buffer layer層鉑之厚度,並利用震動樣品磁度儀(VSM)及超導量子干涉儀(SQUIDE)分別量測垂直及平行磁場方向之磁化強度M對磁場field H的關係,再由M-H圖進行判別其垂直異向性的程度。
在最初的實驗部分可了解如何得到最佳(鈷/鉑)垂直異向性多層膜之結構,並從中可得不同緩衝層鉑之厚度、(鈷/鉑)雙層層數及雙層內鉑之厚度的矯頑場有一趨勢存在,於第二部分的實驗即利用這些矯頑場之趨勢來製作一系列產生巨磁效應之三層膜結構,其中的鐵磁層由(鈷/鉑)垂直異向性多層膜取代,並對此結構做一系列量測,利用震動樣品磁度儀(VSM)量測其磁化強度對磁場的關係、利用LR700系統及物理低溫量測系統(PPMS)量測其異常Hall effect霍爾效應(EHE)現象和電阻對磁場的關係,再將這一系列的量測結果分析其中被一般金屬層鉑所隔開的上下(鈷/鉑)垂直異向性多層膜之間耦合程度。 / The topic of this thesis is about the property of the interface and structure in the multilayers with perpendicular anisotropy. The materials of this multilayers are ferromagnetic cobalt and platinum. We use sputtering system to fabricate cobalt/platinum multilayer with various thicknesses. The initial experiment is to search for the optimum condition that develop cobalt/platinum multilayer with perpendicular anisotropy. Then, the influenceof the buffer layer of platinum is studied. We use Vibrating sample magnetometer (VSM) and superconducting quantum interference device (SQUID) magnetometer to measure the magnetization vs. magnetic field relation by applied magnetic fields in both out of plane and in plane directions to distinguishe the degree of perpendicular anisotropy from the M-H figures.
From the initial experiments we can understand how to get the optimum structure of cobalt/platinum perpendicular anisotrpy multilayer. There is a tendency exists in the coercivity depending on different thicknesses of the ferromagnetic layer cobalt, the normal noble platinum, the number of bilayers of cobalt/platinum, and the buffer layer of platinum. In the second part of this experiment we used the difference of coercivities to fabricate a series of trilayers structures that produce giant magnetoresistance effect. The individual ferromagnetic layer was cobalt/platinum perpendicular anisotropy multilayer. The structures was measured by VSM to study magnetization vs. field relation. A LR700 resistance bridge and a physical properties measurement system (PPMS) were used to measure the Anomalous Hall Effect (AHE) and resistant vs. field relation.
Identifer | oai:union.ndltd.org:CHENGCHI/G0098755007 |
Creators | 曾嘉裕, Tseng, Chia Yu |
Publisher | 國立政治大學 |
Source Sets | National Chengchi University Libraries |
Language | 中文 |
Detected Language | English |
Type | text |
Rights | Copyright © nccu library on behalf of the copyright holders |
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