【摘要】：現(xiàn)代科學(xué)技術(shù)的不斷發(fā)展和完善對硬盤磁盤等磁性信息存儲器件的存儲性能要求越來越高,研究設(shè)計(jì)更快速度和更高密度的磁性存儲器件是研究者們一直致力研究的議題。由于磁性存儲器件在生活中應(yīng)用廣泛,因此如何提高磁性材料的存儲性能就顯得非常重要,其中磁性材料的磁矩翻轉(zhuǎn)問題是一個(gè)非常重要的研究課題,即如何提高磁性材料磁矩翻轉(zhuǎn)效率以及降低其翻轉(zhuǎn)過程中的翻轉(zhuǎn)場等問題。磁性存儲器件的存儲密度和速度難以滿足日新月異的科技發(fā)展對材料存儲性能的要求,因此我們需要不斷發(fā)展磁性存儲技術(shù)以及信息快速存儲與讀取技術(shù)。磁性材料的磁矩翻轉(zhuǎn)過程是極其復(fù)雜的,為了方便研究,本篇論文使用簡化的單軸斯托納粒子模型來研究磁矩翻轉(zhuǎn)過程的動(dòng)力學(xué)性質(zhì),這樣不但可以大幅度節(jié)省時(shí)間還可以給實(shí)際應(yīng)用帶來一定的指導(dǎo)作用。本論文主要對變頻橢圓微波場下斯托納粒子磁矩翻轉(zhuǎn)的動(dòng)力學(xué)性質(zhì)以及微波場輔助傾斜極化自旋極化電流磁矩翻轉(zhuǎn)的動(dòng)力學(xué)性質(zhì)進(jìn)行研究。文章的基本結(jié)構(gòu)如下:第一章是引言,主要對本研究領(lǐng)域的背景和發(fā)展情況做簡單介紹,并通過對領(lǐng)域內(nèi)重要文獻(xiàn)的梳理解讀進(jìn)一步理解本領(lǐng)域的研究進(jìn)展。第二章是理論基礎(chǔ)部分,主要介紹了研究磁矩翻轉(zhuǎn)的基本方程即朗道-栗弗席茲-吉爾伯特(LLG)方程及其推導(dǎo)過程,并介紹了考慮自旋力矩項(xiàng)后的Landau-Lifshitz-Gilbert-Slonczewski(LLGS)方程。第三章研究的是橢圓偏振微波場輔助斯托納粒子磁化矢量翻轉(zhuǎn)的動(dòng)力學(xué)性質(zhì),基于朗道-栗弗席茲-吉爾伯特方程研究磁矩翻轉(zhuǎn)過程,考慮磁性單軸各向異性,通過分析及模擬研究磁矩翻轉(zhuǎn)所需的臨界翻轉(zhuǎn)場和變化的微波頻率幅度之間的關(guān)系。研究表明當(dāng)橢圓偏振波兩個(gè)方向的頻率均接近鐵磁共振頻率時(shí),會(huì)出現(xiàn)最小臨界翻轉(zhuǎn)場。第四章研究的是橢圓偏振微波場輔助傾斜極化自旋極化電流磁矩翻轉(zhuǎn)的動(dòng)力學(xué)性質(zhì)�？紤]粒子的磁性單軸各向異性,文章基于Landau-Lifshitz-Gilbert-Slonczewski(LLGS)方程,通過分析和模擬研究不同構(gòu)型磁性自旋閥磁矩翻轉(zhuǎn)過程中所需的閾值電流密度和微波場的幅度頻率之間的關(guān)系。研究表明傾斜構(gòu)型的磁性自旋閥可以有效地降低自由層磁矩翻轉(zhuǎn)過程中所需的閾值電流密度。第五章是總結(jié)和展望章節(jié),主要對研究工作進(jìn)行總結(jié)并針對其中存在的有待解決的問題做出分析和展望。
[Abstract]:The continuous development and improvement of modern science and technology on the hard disk? The storage performance of magnetic information storage devices such as magnetic disks is becoming more and more demanding. The research and design of magnetic memory devices with faster speed and higher density has been the research topic of researchers. Because magnetic memory devices are widely used in daily life, how to improve the storage performance of magnetic materials is very important. Among them, the magnetic moment reversal of magnetic materials is a very important research topic. That is, how to improve the efficiency of magnetic moment reversal and reduce the turnover field. The storage density and speed of magnetic memory devices can not meet the requirement of material storage performance due to the rapid development of science and technology, so we need to develop magnetic storage technology and information fast storage and reading technology. The magnetic moment reversal process of magnetic materials is extremely complex. In order to facilitate the study, a simplified single-axis Stogner particle model is used to study the dynamic properties of the magnetic moment inversion process. In this way, it can not only save time greatly, but also bring some guidance to practical application. In this paper, the dynamic properties of the magnetic moment reversal of the Stoner particle under the frequency conversion elliptical microwave field and the dynamic properties of the magnetic moment reversal of the inclined polarization spin polarization current assisted by the microwave field are studied. The basic structure of the paper is as follows: the first chapter is the introduction, mainly introduces the background and development of this research field, and further understand the research progress through the combing and reading of the important literature in the field. The second chapter is the theoretical basis, mainly introduces the fundamental equation of magnetic moment reversal, i.e. Lando-Lifschitz Gilbert (LLG) equation and its derivation process. The Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation considering the spin moment term is also introduced. In chapter 3, the dynamical properties of magnetization vector flipping assisted by elliptical polarization microwave field are studied. The magnetic moment inversion process is studied based on Lando-Lifschitz Gilbert equation, and the magnetic uniaxial anisotropy is considered. The critical flipping field and the changing microwave frequency of magnetic moment flipping are studied by means of analysis and simulation. The relationship between ranges. It is shown that when the frequency of elliptical polarization wave in both directions is close to the frequency of ferromagnetic resonance, the minimum critical inversion field will occur. In chapter 4, the dynamical properties of the magnetic moment reversal of the inclined spin polarization current assisted by the elliptical polarization microwave field are studied. Considering the magnetic uniaxial anisotropy of particles, based on Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation, the threshold current density and the amplitude of microwave field during magnetic moment reversal of magnetic spin valves with different configurations are analyzed and simulated. The relationship between frequencies. It is shown that the inclined magnetic spin valve can effectively reduce the threshold current density required in the free layer magnetic moment reversal process. The fifth chapter is the summary and prospect chapter, mainly summarizes the research work and makes the analysis and prospect in view of the problems to be solved.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：O482.54;TP333

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本文編號：2425333