优秀博士硕士学位论文评选办法(共12页)

1、PAGE PAGE 13附1：内蒙古师范大学优秀博（硕）士学位(xuwi)论文推荐表学院(xuyun)名称： 物理(wl)与电子信息学院 学科、专业： 理论物理 论文题目二维三组元磁振子晶体的带结构论文英文题目Band Structures of Two-Dimensional Magnonic Crystal with Three Components作者姓名论文答辩日期获得博士（硕士）学位日期论文涉及的研究方向丁秋月2014年5月28日 2014年7 月计算物理一级学科代码一级学科名称二级学科代码二级学科名称是否自设学科专业0702物理学070201理论物理否指导教师姓名（限填1人）指导教

2、师研究方向作者攻博（硕）期间及获博（硕）士学位后一年内获得与博（硕）士学位论文密切相关的代表性成果序号成果名称成果出处获得年月查询信息1二维三组元局域共振磁振子晶体带隙结构的优化 河北师范大学2014年5月ISSN 1000-58542自旋波在磁振子晶体中的传播与局域性质内蒙古师范大学2012年度研究生科研创新基金2012年7月CXJJS 120323平面波展开法计算一维薄板磁振子晶体带结构信息记录材料2013年4月ISSN 1009-562445论文主要创新点 本文主要引入了二维三组元磁振子晶体的结构单元。计算了相应的带结构、态密度和场分布情况，通过与相同参数下二组元的情况进行对比发现，产生

3、了低频带隙，并可以通过包覆层的厚度和整体的整体填充率实现带隙结构的优化。本人保密承诺按国家、省有关保密规定，经审查，本学位论文不涉密，可在互联网上公开评审。本人签字： 年 月 日答辩委员会意见学位论文得分 ： 答辩委员会主席（签章）： 年 月 日 培养单位意见负责人（签章）： 年 月 日 学位评定分委员会意见 学位评定分委员会主席（签章）： 年 月 日校学位评定委员会意见校学位评定委员会主席（签章）： 单位公章： 年 月 日注：自主设置学科专业代码及名称须与报国务院学位委员会办公室备案时一致。请再填写一个与自设二级学科相近的现有(xin yu)学科目录中的二级学科代码和名称，填写格式为“自设二

4、级学科代码(di m)名称（相近学科代码名称）”。“代表性成果(chnggu)”限填所有各年度作者攻博（硕）期间及获博（硕）士学位后一年内获得与学位论文密切相关的、并能反映学位论文水平的成果。可填学术论文、专著、专利、奖励等，但总数不得超过5项。成果必须是在规定时间内公开发表（含网络在线发表）或审批的，已录用、已受理和无批文的成果一律不计入。请准确填写各项成果的查询信息，确保按此查询信息能查询到该成果，以便于专家评议时核查。“成果名称”栏，可填写论文题目、专著名称、专利名称、奖励名称等。“成果(chnggu)出处”栏，可填写(tinxi)刊物名称、出版机构、奖励发放单位等。“获得(hud)年月

5、”栏，可填写论文公开发表、专著公开出版、专利授予、奖励获批的具体年月。“成果查询信息”栏，应填写论文检索号、国际标准书号（ISBN）、专利号、获奖证书号等。填写“检索号”时，若论文被SCI、SSCI、EI、A&HCI检索，则填写论文检索号；否则填写刊物的出版年期。附2：论文中、英文摘要格式作者姓名：丁秋月论文题目：二维三组元磁振子晶体的带结构作者简介：丁秋月，女，1987年7月出生，2011年9月师从于内蒙古师范大学曹永军教授，于2014年6月获硕士学位。中 文 摘 要近年来，大量的论文已经致力于研究如超晶格的磁性复合材料的一维磁振子能带结构问题大多数这些文章像Albuquerque及其他人所

6、计算研究的，都专注于在磁性超晶格中，存在于自旋波频谱内的自旋波带隙由两个交替方向的铁磁层所构成的一个无限超晶格中，在所计算出来的自旋波传播的色散方程中发现，一定的频率范围内，超晶格中的自旋波色散曲线表现出宽通带和窄禁带随之，开始了对两种不同磁性材料周期性交替排列所构成的一维二组元磁振子晶体的计算研究新加坡的王智魁等人研究了由Permalloy和Cobalt两种材料的纳米条纹交替周期性排列组成的一维磁振子晶体的自旋波传播性质、磁振子带隙的宽度和其中心频率随外磁场的变化关系，以及纳米条纹的宽度值对带隙宽度的影响1996年法国的J. O. Vasseu等人以及波兰的H. Puszkarski等人构造

7、了由无限长的圆柱铁散射体周期排列在另外一种铁磁材料基底中的二维磁振子晶体，计算了晶格常数在纳米量级范围内自旋波的带结构研究表明，散射体之间的交换作用影响着带隙的形成，且带隙的宽度是和交换作用成正比的同时也发现带隙形成及带隙宽度和饱与磁化强度以及散射体体积填充率等有关2008年M. Krawczyk和H. Puszkarski等人构造了三维铁磁材料所构成的磁振子晶体，并计算研究了相应的带结构计算结果显示了磁振子晶体带隙的形成及带隙宽度与磁参数有密切的关系2010年曹永军等人针对短波微扰的情况，只考虑交换作用，改进了传统的平面波展开法用改进的平面波法进行计算可以节省很大一部分计算时间，提高工作效率

8、在本文中就是使用改进平面波法进行的数值计算 实验时，理想晶体很难达到，所以英国的V. V. Kruglyaka及乌克兰的A. N. Kuchko等人研究了磁振子晶体中存在缺陷的情况计算表明了缺陷的存在使得磁振子晶体带隙内出现了局域模,证明了缺陷态对自旋波的传播具有局域的作用 虽然对磁振子晶体的研究越来越多，但目前对于由于制作磁振子晶体技术的限制，对磁振子晶体的应用很少，主要的研究集中于理论和实验阶段磁振子晶体的概念由光子晶体、声子晶体引申而来，是磁性材料的超晶格结构，由二种（或以上）磁性材料在空间周期排列构成国内外已有初步的理论和实验研究工作均表明，磁振子晶体会对铁磁复合材料里的自旋波进行操纵

9、，在一定的条件下会有空白频谱即自旋波带隙形成，处于带隙频率范围内的自旋波模式是不容许在磁振子晶体复合材料中传播的利用自旋波带隙特性的可裁剪性，通过人为的结构或参数设计，可以关闭或打开一定频率的带隙具有自旋波带隙的磁振子晶体在微波领域像微波滤波器、开关、电流控制延迟线等器件的制作材料领域内有潜在的应用价值所以，带隙的优化和调控变成了当今纳米器件领域的研究热点本课题组通过调节散射体的形状、排列方式、填充率等因素以及围绕应用设计恰当的缺陷结构，系统地研究了布拉格机制下的磁振子晶体系统中带隙结构优化问题和自旋波缺陷态的性质基于局域共振思想的启发，本文中首次构造了二维三组元的磁振子晶体三组元磁振子也是磁

10、振子晶体的一种，是由散射体、包覆层、基底三种组元材料共同复合而成的通过对其带结构及磁化强度场分布的计算研究，发现三组元磁振子晶体的带结构有独特的优势所在经过计算，二维三组元的磁振子晶体有低频的带隙出现，可实现低频自旋波的可控操作且通过对带结构和磁振子态密度分布图的计算，发现态密度的分布与带隙位置非常吻合以往研究的磁振子晶体都是有两种材料复合而成的，本文中主要构造了二维三组元磁振子晶体，散射体是由两种材料所构成的研究自旋波在二维三组元磁振子晶体中的传播特性，利用改进的平面波展开法数值的计算了二维三组元磁振子晶体的带结构、态密度、能量局域情况晶体单元的改变主要包括三种组分总的填充率的改变，以及单原

11、胞中包覆层的厚度的改变本文主要通过对单元胞填充率及中心圆柱和涂层圆柱半径比的优化设计，探索其对二维三组元磁振子晶体单原胞带结构特性的影响，获得了调节二维三组元磁振子晶体材料的禁带频率的有效途径第一章主要推导了三组元磁振子晶体的傅里叶系数，并且考虑到，自旋波的波长是短波的情况下，短程的交换作用起主要作用，所以静磁项可以忽略不计在这种近似下，利用改进的平面波展开法推导出了相应的本征方程本文的第二章中，研究了所构造的二维三组元磁振子晶体特征，利用平面波法计算了其带结构与其态密度，并与未包裹的情况进行了比较，结果发现可以通过包裹第三种材料来进行带隙的优化在第三章主要研究的是影响二维三组元磁振子晶体带结

12、构中禁带频率范围的一些参数，比如整体涂层柱的填充率和包覆层的厚度计算并分析了不同参数下的自旋波禁带频率，改变包覆层厚度和涂层柱的填充率去探究它的变化曲线，通过改变这些参数可以进一步优化磁振子晶体的带结构通过平面波展开法，计算了二维三组元磁振子晶体的带结构和态密度，同时也通过与二维二组元的情况进行对比发现有低频带隙的产生，并且计算了三点的场分布情况，以及通过调整涂层柱填充率和中心圆柱与涂层柱的半径比的进行带隙的优化数值计算结果表明，对本文选取的系统，最宽的第一带隙出现在填充率和半径比为的时候最宽的第二带隙出现在填充率和半径比为的时候通过两个变化曲线可以根据需要进行带结构的优化，获得最大禁带宽度如

13、若固定了半径比，则可以选择附近的填充率去获得最大带隙本文基于二维三组元的低频自旋波带隙的产生及其优化问题的研究，为利用磁振子晶体实现低频自旋波的可控操作提供了一种途径以上的研究结果，可以使二维三组元磁振子晶体在一些实际器件的制造时提供理论意义上的帮助本文中二维三组元磁振子晶体的提出是为了优化磁振子晶体的带结构，利用三组分来优化带隙的思想来源于局域共振结构散射机制有两种，一种为布拉格散射机制，另一种为局域共振机制在本文中，是布拉格散射的机制起着主要的作用局域共振结构中带隙不是来自于布拉格散射机制，而是来源于局域共振的作用，通过基底材料和中心圆柱材料间的振动耦合，使得共振振幅达到最大希望可以在以后

14、的工作中，设计包覆层氧化铕材料较中心柱和基底材料为软磁材料，能够使带隙边缘较密集的“振动”模式集中在散射体或包覆层内部，从而形成局域共振机制的磁振子带隙.当然，这里的“振动”二字只是借鉴了声学领域的一个名词,这里并非一种实际的振动，而是一种磁化过程但我们仍然沿用声学领域的提法，“局域共振”也是如此得名局域共振机制相比布拉格散射机制有个突出的特点，局域共振机制并不要求周期性结构的晶格常数与自旋波的波长相比拟，周期性结构的单元可以远远小于自旋波的波长，而布拉格机制要求晶格常数与电磁波的波长相比拟磁振子晶体的晶格常数常在纳米量级甚至纳米以下，这样在制作时就对工艺技术要求是非常高的因此，局域共振机制可

15、以突破布拉格散射机制的限制，在不考虑晶格常数与自旋波波长相比拟的前提下产生带隙或实现自旋波的可控操作，在磁振子晶体的领域有着很大的应用优势和发展潜力由于纳米技术重大进展和磁性材料的实验技术，磁振子晶体成为了一种新型的跨学科的研究领域除了明显的挑战，也有许多令人兴奋的尚未开发的机会以及在实际应用中的巨大潜力希望本论文将通过研究可以磁振子领域对新的挑战和应用提供一些理论依据对磁振子晶体中自旋波带结构特性的进一步研究，一定能够发现更多新的物理现象，对磁振子晶体以及物理学的发展有着重要的意义，也将会拓展更多新的应用领域纵览磁振子晶体领域的研究现状与应用前景，本文中将提出的三组元磁振子晶体在本项目中有重

16、要的理论意义和巨大应用潜力关键词： 三组(sn z)元磁振子晶体，自旋波，带隙，平面波展开法Band Structures of Two-Dimensional Magnonic Crystal with Three ComponentsDing Qiu Yue ABSTRACTIn recent years, the one-dimensional magnetic vibrator lots of papers have been devoted to the study of magnetic composite materials such as superlattice band s

17、tructures. Most of these articles like Albuquerque and others have computing research, are focused on in magnetic superlattices, spin wave gap exists in the spin wave spectrum is composed of two. Alternating direction of the ferromagnetic layer of an infinite superlattice, found in the spin wave dis

18、persion equations have been calculated in, a certain frequency range, the spin wave in the superlattice dispersion curves exhibit a wide band and narrow band gap. Then, the calculation of the beginning of two different magnetic one-dimensional periodic material alternating arrangement consisting of

19、two component magnetic oscillator crystal. Wang Zhikui, Singapores study of the relationship by Permalloy and Cobalt of two kinds of materials of nano stripes alternating periodic one-dimensional magnon crystals composed of spin wave propagation properties, the magnon band gap width and the center f

20、requency with the external magnetic field, and the width of nano stripes effect on band gap width.1996年法国的J. O. Vasseu等人74以及波兰的H. Puszkarski等人75构造了由无限长的圆柱铁散射体周期排列在另外一种铁磁材料基底中的二维磁振子晶体，计算了晶格常数在纳米量级范围内自旋波的带结构研究表明，散射体之间的交换作用影响着带隙的形成，且带隙的宽度是和交换作用成正比的同时也发现带隙形成及带隙宽度和饱与磁化强度以及散射体体积填充率等有关IIIIIn 1996 Frances J

21、. O. Vasseu and Polands H. Puszkarski, et al is constructed by the cylindrical iron scattering periodic infinite array of two-dimensional magnetic dipole in a ferromagnetic material in the substrate crystal lattice constant, spin in nanometer range wave band structure calculation. In the study, exch

22、ange scattering between the body affects the formation of the band gap, and the band gap width is proportional to the switching function. At the same time, also found that the band gap formation and the width of band gap and saturated magnetization and the scattering volume filling ratio and so on.2

23、008年M. Krawczyk和H. Puszkarski等人83构造了三维铁磁材料所构成的磁振子晶体，并计算研究了相应的带结构计算结果显示了磁振子晶体带隙的形成及带隙宽度与磁参数有密切的关系In 2008 M. Krawczyk and H. Puszkarski et al. constructed magnon crystals made of three dimensional ferromagnetic materials, and the corresponding calculation of band structure. The calculation results sho

24、w that the magnetic dipole formed crystal band gap and the close relationship between the width of band gap and magnetic parameters.2010年曹永军等人针对短波微扰的情况，只考虑交换作用，改进了传统的平面波展开法用改进的平面波法进行计算可以节省很大一部分计算时间，提高工作效率在本文中就是使用改进平面波法进行的数值计算In 2010 Cao Yongjun et al for the short wave perturbation case, considering

25、 only the exchange interaction, improved the traditional plane wave expansion method. Using the plane wave method improved calculation can save a large amount of computing time, improve work efficiency. Numerical calculation of improved plane wave method is used in this paper.实验时，理想晶体很难达到，所以英国的V. V.

26、 Kruglyaka及乌克兰的A. N. Kuchko等人84,85研究了磁振子晶体中存在缺陷的情况计算表明了缺陷的存在使得磁振子晶体带隙内出现了局域模,证明了缺陷态对自旋波的传播具有局域的作用During the experiment, it is difficult to achieve the ideal crystal, so Britains V. V. Kruglyaka and Ukraine N. Kuchko A. et al studied the existence of Magnon crystals. The calculated results show that

27、the defects that appear in the band gap of localized magnon crystals, demonstrate the spreading defect states on the spin wave with local role.The group has investigated the optimizing problems of spin-wave gaps with the mechanism of Bragg scattering by changing the shape, the arrangement and the fi

28、lling fraction of scatterers embedded in matrix, and investigated the properties of defect states by designing available defect structure in magnonic crystals. Based on the idea of localized resonance, a two-dimensional magnonic crystal with three components is presented in this thesis at the first

29、time. The three-component magnonic crystal composed of the scatterer, the coating layer and the matrix. After the calculating of band structures and field distributions of magnetization, we have found that some remarkable advantages in the three-component magnonic crystal generating low-frequency ga

30、ps, and so the spin wave with low frequency can be controlled by using this kind of magnetic composite materials. Density of states of magnons in the magnonic crystal also has been calculated, and the same results as the band structures can be obtained.Previous studies of the magnon crystals are two

31、 kinds of material compound and into, this paper builds a two-dimensional three component magnon crystals, scattering body is composed of two kinds of materials. Study on propagation of spin waves in 2D three component magnetic dipole in the crystal, expansion method numerical the two-dimensional th

32、ree component magnetic oscillator crystal band structure, density of States, energy localization by plane wave. The improved crystal unit change mainly comprises three components: the total filling rate of change, and change the thickness of coated layer in single cells.This paper mainly through the

33、 filling ratio optimization design of rate and central cylinder and coated cylinder radius on the unit cell, and explore its effect on 2D three component magnetic oscillator crystal single cell with the structure characteristics of the band gap, effective way to adjust the frequency of 2D three comp

34、onent magnetic oscillator crystal material.The first chapter mainly deduces the Fourier coefficients of the three element magnon crystals, and taking into account, the wavelength of the spin waves is the short wave case, exchange short plays the main role, so the static magnetic items can be ignored

35、. In this approximation, by using the improved plane wave expansion method to derive the eigenvalue equation the corresponding.The second chapter of this paper, to study the two-dimensional structure of the three component magnetic oscillator crystal characteristics, using the plane wave method is i

36、ntroduced to calculate the band structure and density of States, and compared with the uncoated condition, results can be found to optimize the band gap by parcel third kinds of material.The main research in the third chapter is the influence of some parameters of 2D three component magnetic oscilla

37、tor crystal band frequency range of band gap structure, such as the whole coating column filling rate and coating thickness. Analysis of the spin wave gap frequency under different parameters are calculated and, change the fill rate of coating thickness and coating column to explore change curve of

38、it, the band structure of Magnon crystals by changing these parameters can be optimized further. By the plane wave expansion method, band structure and density of states of the two-dimensional three component magnetic oscillator crystal were calculated, and compared with the 2D two component of low

39、band gap is found, field three the distribution of points and calculated, and by adjusting the coated column fill rate and central cylinder and coated column radius ratio to optimize the band gaps. The numerical results show that, the system in this paper, the first band gap width appeared in the fi

40、lling ratio and radius ratio when the width of second. The band gap appears in the filling ratio and radius ratio of time. By two change curve can be optimized with structure according to the need, the maximum width of the gap. If fixed radius ratio, then You can choose to obtain the maximum filling

41、 rate near the band gap. This paper research on optimization problem of low-frequency spin wave gap of 2D three component based, and provides a way to use the magnon crystals to achieve controllable operating frequency spin waves. The results of the study above, the 2D three component magnetic vibra

42、tor crystal provides theoretical help in making some real devices.In this paper, the two-dimensional three component magnetic oscillator crystal structure optimization is to bring the magnon crystals, using three component to optimize the band gap of the thought originates from the local resonance s

43、tructure. The scattering mechanism has two kinds, one kind is the Prague scattering mechanism, another is the local resonance mechanism. In this paper the mechanism, is the Prague scattering plays a major role. Not from the Prague scattering mechanism of band gap structure of local resonance in the

44、role, but from local resonance, vibrational coupling through the substrate material and the center cylinder between materials, so that the resonance amplitude reached the maximum. Hope I can work in the future, coated layer of europium oxide the material is a central column and the base material for

45、 soft magnetic materials, can make the band gap edge dense vibration mode in scattering or coating, the magnon so as to form a local resonance band gap. However, here the vibration two words just draw a noun acoustic field here, not an actual vibration, but a magnetization process. But we still use

46、the acoustic field formulation, local resonance is so named. Local resonance compared Bula Lattice scattering mechanism is a prominent feature, local resonance mechanism does not require the periodic structure of the lattice constant and the spin wave wavelength, periodic structure unit can be far l

47、ess than the wavelength of the spin waves, while Prague mechanism requires wavelength and lattice constant of electromagnetic wave. The lattice constant compared to magnon crystals often in the nanometer and nanometer, so in production requires the technology is very high. Therefore, local resonance

48、 Prague scattering mechanism can break through the limit, regardless of the lattice constant and the spin wave appearance than the quasi under the premise of band gap or controlled operation of spin waves, with the advantages and development a great potential in the magnon crystal field.Because of experimental technology major advances in nanotechnology and magnetic materials, magnetic oscillator crystal have become a new interdisciplinary research field. In addition to the obvious challenge, also have the opportunity to many an untappe