自旋軌道力矩已經被提出是下一個世代磁阻式隨機存取記憶體的寫入方式，極具發展潛力，許多學者開始投入此領域進行深入研究。本實驗之水平白金錳/鈷鐵硼系統即為研究水平的自旋軌道力矩翻轉，其優勢除了寫入速度快之外，臨界翻轉電流也較低，且其翻轉過程不需要額外施加外加場幫忙。
本實驗主要透過磁力顯微鏡(MFM)與水平聚焦式科爾儀(L-MOKE)對已序化之白金錳/鈷鐵硼系統進行自旋軌道力矩翻轉的分析。整個實驗過程中的濺鍍膜層、黃光微影、離子束蝕刻皆在我們實驗室完成，我們將元件做成霍爾長方，盡量提高白金錳的厚度，並且降低其他層的厚度，以提升白金錳層的電流密度，最終我們能成功達成零場翻轉，其臨界電流密度為3.78*107 A/cm2，在量測磁滯曲線之後，我們更是發現其交換場隨者自旋軌道力矩的翻轉也跟著翻動了。並且我們也調整了白金錳的厚度與膜層順序來進行比較。

Spin-orbit torque (SOT) switching has been proposed to be the most promising writing scheme for next-generation magnetic random access memory (MRAM). SOT with an orthorhombic current/in-plane magnetization geometry which has demonstrated its potential on the deterministic switching dynamics and low-power consumption.
In this work, we exhibit the field-free SOT switching in a PtMn/CoFeB bilayer studied by using a magnetic force microscope (MFM) and amagneto-optical Kerr magnetometer (MOKE). The Whole process fabricating the devices has been done in our lab myself, such as film sputtering, photolithography, and ion beam etching. We fabricate the device into hall bar structure. We increase the thickness of PtMn layer and reduce the thickness of others in order to reduce the critical current for switching. PtMn is an antiferromagnet with considerable spin Hall Effect as typical heavy metals, which is capable of triggering the magnetization switching of adjacent CoFeB with a critical current density of 3.78*107 A/cm2. Furthermore, the hysteresis loops acquired from the two magnetic states show a clear variation on exchange bias (±160 Oe), suggesting the spin configuration at the PtMn/CoFeB interface can be modified by the spin Hall effect from PtMn itself. At the same time, we change the thickness of PtMn and the order of deposition to make some comparison and discussion.

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