{"title":"不同磁晶各向异性类型单轴晶体 180° 域壁的能量","authors":"A.I. Sinkevich, M.B. Lyakhova, E.M. Semenova","doi":"10.1016/j.jmmm.2024.172560","DOIUrl":null,"url":null,"abstract":"<div><div>The main aim of the present work is to analyze the magnetocrystalline anisotropy (MCA) energy function of uniaxial crystals and to derive analytical expressions for the domain wall (DW) energy taking into account two MCA constants. Thus, the article presents a detailed analysis of the magnetocrystalline anisotropy energy function of uniaxial crystals taking into account two MCA constants (<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>). The values of the MCA energy extremes and the position of the easy magnetization directions (EMD) and hard magnetization directions (HMD) were determined. The MCA diagram was plotted in “<em>K<sub>1</sub></em>”-“<em>K<sub>2</sub></em>” coordinates. Six types of MCA have been found for uniaxial crystals. Two of them are simple with one maximum and one minimum of the <em>E<sub>A</sub></em>(<em>θ</em>) function, and four are complex with two absolute and one local extreme for each. It is shown that <em>E<sub>A</sub></em>(<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>) function has the smallest difference between the maximum and minimum values equal to |<em>K<sub>1</sub></em>|/4 and the smallest angle between EMD and HMD equal to π/4 when the <em>K<sub>1</sub></em> + <em>K<sub>2</sub></em> = 0 condition is met. Analytical expressions for the 180° Bloch domain wall energy surface density (γ) were derived for uniaxial crystals with each MCA type. It is found that the γ(<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>) function has a minimum, equal to <span><math><mrow><mi>γ</mi><mo>=</mo><mn>2</mn><msqrt><mrow><mrow><mi>A</mi><mo>|</mo></mrow><msub><mi>K</mi><mn>1</mn></msub><mrow><mo>|</mo></mrow></mrow></msqrt></mrow></math></span> when the relation <em>K<sub>1</sub></em> + <em>K<sub>2</sub></em> = 0 between MCA constants is satisfied. The derived analytical expressions are useful for a detailed spin-reorientation transition analysis. To illustrate this, examples of the application of the obtained results to MCA analyses of real crystals and DW energy calculations are given.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"610 ","pages":"Article 172560"},"PeriodicalIF":2.5000,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The energy of 180° domain walls of uniaxial crystals with the different magnetocrystalline anisotropy type\",\"authors\":\"A.I. Sinkevich, M.B. Lyakhova, E.M. Semenova\",\"doi\":\"10.1016/j.jmmm.2024.172560\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The main aim of the present work is to analyze the magnetocrystalline anisotropy (MCA) energy function of uniaxial crystals and to derive analytical expressions for the domain wall (DW) energy taking into account two MCA constants. Thus, the article presents a detailed analysis of the magnetocrystalline anisotropy energy function of uniaxial crystals taking into account two MCA constants (<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>). The values of the MCA energy extremes and the position of the easy magnetization directions (EMD) and hard magnetization directions (HMD) were determined. The MCA diagram was plotted in “<em>K<sub>1</sub></em>”-“<em>K<sub>2</sub></em>” coordinates. Six types of MCA have been found for uniaxial crystals. Two of them are simple with one maximum and one minimum of the <em>E<sub>A</sub></em>(<em>θ</em>) function, and four are complex with two absolute and one local extreme for each. It is shown that <em>E<sub>A</sub></em>(<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>) function has the smallest difference between the maximum and minimum values equal to |<em>K<sub>1</sub></em>|/4 and the smallest angle between EMD and HMD equal to π/4 when the <em>K<sub>1</sub></em> + <em>K<sub>2</sub></em> = 0 condition is met. Analytical expressions for the 180° Bloch domain wall energy surface density (γ) were derived for uniaxial crystals with each MCA type. It is found that the γ(<em>K<sub>1</sub></em>, <em>K<sub>2</sub></em>) function has a minimum, equal to <span><math><mrow><mi>γ</mi><mo>=</mo><mn>2</mn><msqrt><mrow><mrow><mi>A</mi><mo>|</mo></mrow><msub><mi>K</mi><mn>1</mn></msub><mrow><mo>|</mo></mrow></mrow></msqrt></mrow></math></span> when the relation <em>K<sub>1</sub></em> + <em>K<sub>2</sub></em> = 0 between MCA constants is satisfied. The derived analytical expressions are useful for a detailed spin-reorientation transition analysis. To illustrate this, examples of the application of the obtained results to MCA analyses of real crystals and DW energy calculations are given.</div></div>\",\"PeriodicalId\":366,\"journal\":{\"name\":\"Journal of Magnetism and Magnetic Materials\",\"volume\":\"610 \",\"pages\":\"Article 172560\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-09-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Magnetism and Magnetic Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0304885324008515\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Magnetism and Magnetic Materials","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304885324008515","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
The energy of 180° domain walls of uniaxial crystals with the different magnetocrystalline anisotropy type
The main aim of the present work is to analyze the magnetocrystalline anisotropy (MCA) energy function of uniaxial crystals and to derive analytical expressions for the domain wall (DW) energy taking into account two MCA constants. Thus, the article presents a detailed analysis of the magnetocrystalline anisotropy energy function of uniaxial crystals taking into account two MCA constants (K1, K2). The values of the MCA energy extremes and the position of the easy magnetization directions (EMD) and hard magnetization directions (HMD) were determined. The MCA diagram was plotted in “K1”-“K2” coordinates. Six types of MCA have been found for uniaxial crystals. Two of them are simple with one maximum and one minimum of the EA(θ) function, and four are complex with two absolute and one local extreme for each. It is shown that EA(K1, K2) function has the smallest difference between the maximum and minimum values equal to |K1|/4 and the smallest angle between EMD and HMD equal to π/4 when the K1 + K2 = 0 condition is met. Analytical expressions for the 180° Bloch domain wall energy surface density (γ) were derived for uniaxial crystals with each MCA type. It is found that the γ(K1, K2) function has a minimum, equal to when the relation K1 + K2 = 0 between MCA constants is satisfied. The derived analytical expressions are useful for a detailed spin-reorientation transition analysis. To illustrate this, examples of the application of the obtained results to MCA analyses of real crystals and DW energy calculations are given.
期刊介绍:
The Journal of Magnetism and Magnetic Materials provides an important forum for the disclosure and discussion of original contributions covering the whole spectrum of topics, from basic magnetism to the technology and applications of magnetic materials. The journal encourages greater interaction between the basic and applied sub-disciplines of magnetism with comprehensive review articles, in addition to full-length contributions. In addition, other categories of contributions are welcome, including Critical Focused issues, Current Perspectives and Outreach to the General Public.
Main Categories:
Full-length articles:
Technically original research documents that report results of value to the communities that comprise the journal audience. The link between chemical, structural and microstructural properties on the one hand and magnetic properties on the other hand are encouraged.
In addition to general topics covering all areas of magnetism and magnetic materials, the full-length articles also include three sub-sections, focusing on Nanomagnetism, Spintronics and Applications.
The sub-section on Nanomagnetism contains articles on magnetic nanoparticles, nanowires, thin films, 2D materials and other nanoscale magnetic materials and their applications.
The sub-section on Spintronics contains articles on magnetoresistance, magnetoimpedance, magneto-optical phenomena, Micro-Electro-Mechanical Systems (MEMS), and other topics related to spin current control and magneto-transport phenomena. The sub-section on Applications display papers that focus on applications of magnetic materials. The applications need to show a connection to magnetism.
Review articles:
Review articles organize, clarify, and summarize existing major works in the areas covered by the Journal and provide comprehensive citations to the full spectrum of relevant literature.