反铁磁晶体 Ho0.75Nd0.25Fe3(BO3)4 中 Ho3+ 和 Nd3+ 离子的 f-f 电子跃迁在自旋定向转变区域的磁圆二色性

IF 2.5 3区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Magnetism and Magnetic Materials Pub Date : 2024-10-24 DOI:10.1016/j.jmmm.2024.172613

A.V. Malakhovskii, V.V. Sokolov, A.L. Sukhachev, I.A. Gudim

{"title":"反铁磁晶体 Ho0.75Nd0.25Fe3(BO3)4 中 Ho3+ 和 Nd3+ 离子的 f-f 电子跃迁在自旋定向转变区域的磁圆二色性","authors":"A.V. Malakhovskii, V.V. Sokolov, A.L. Sukhachev, I.A. Gudim","doi":"10.1016/j.jmmm.2024.172613","DOIUrl":null,"url":null,"abstract":"<div><div>Absorption and magnetic circular dichroism (MCD) spectra have been studied in the region of 5I8 → 5F2, 5S2, 5F3, and 5F5 absorption bands of the Ho3+ ion and in the region of 4I9/2→4G7/2, 2K13/2, 4S3/2, 4F7/2, 4F5/2 and 2H9/2 absorption bands of the Nd3+ ion in an antiferromagnetic trigonal crystal Ho0.75Nd0.25Fe3(BO3)4 in the temperature range from 5 to 90 K. A qualitative change in the shape of the MCD spectra of Ho3+ ion was revealed during the spin-reorientation transition at TR = 6.9 К. Below TR, in the easy-axis state of the crystal, the MCD spectrum has a shape typical for paramagnets, i.e., it consists of diamagnetic and paramagnetic parts. Just above TR, in the easy-plane state of the crystal, MCD of Ho3+ ion has a spectrum similar to the absorption spectrum, which is typical for the paramagnetic part of the MCD. It was shown, that in the easy-plane state the exchange field of iron, being perpendicular to the external field directed along the C3 axis, quenches the usual paramagnetic and diamagnetic MCD in Ho3+ ion, but creates a condition for the appearance of a large paramagnetic MCD of mixing (B-term). With temperature increasing, the MCD spectrum of Ho3+ ion gradually turns into a spectrum typical for paramagnets with the predominance of the sign-changing diamagnetic part, because the influence of the exchange field decreases. The shape of the MCD spectra of Nd3+ ions are typical for paramagnets but does not change during the reorientation transition in the rest of the crystal. This means that the magnetic moment of the Nd3+ ion does not make a reorientation transition simultaneously with the Fe3+ and Ho3+ ions of the rest of the crystal. This phenomenon is accounted for by a strong local magnetic anisotropy of the Nd3+ ion and by a weak exchange interaction Fe-Nd, which is not enough for rotation of the Nd3+ ion moment synchronously with that of the Fe3+ ion. The magneto-optical properties of neodymium are controlled by the easy-axis anisotropy of neodymium.</div></div>","PeriodicalId":366,"journal":{"name":"Journal of Magnetism and Magnetic Materials","volume":"611 ","pages":"Article 172613"},"PeriodicalIF":2.5000,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Magnetic circular dichroism of f-f electron transitions in Ho3+ and Nd3+ ions in antiferromagnetic crystal Ho0.75Nd0.25Fe3(BO3)4 in the region of spin-reorientation transition\",\"authors\":\"A.V. Malakhovskii, V.V. Sokolov, A.L. Sukhachev, I.A. Gudim\",\"doi\":\"10.1016/j.jmmm.2024.172613\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Absorption and magnetic circular dichroism (MCD) spectra have been studied in the region of 5I8 → 5F2, 5S2, 5F3, and 5F5 absorption bands of the Ho3+ ion and in the region of 4I9/2→4G7/2, 2K13/2, 4S3/2, 4F7/2, 4F5/2 and 2H9/2 absorption bands of the Nd3+ ion in an antiferromagnetic trigonal crystal Ho0.75Nd0.25Fe3(BO3)4 in the temperature range from 5 to 90 K. A qualitative change in the shape of the MCD spectra of Ho3+ ion was revealed during the spin-reorientation transition at TR = 6.9 К. Below TR, in the easy-axis state of the crystal, the MCD spectrum has a shape typical for paramagnets, i.e., it consists of diamagnetic and paramagnetic parts. Just above TR, in the easy-plane state of the crystal, MCD of Ho3+ ion has a spectrum similar to the absorption spectrum, which is typical for the paramagnetic part of the MCD. It was shown, that in the easy-plane state the exchange field of iron, being perpendicular to the external field directed along the C3 axis, quenches the usual paramagnetic and diamagnetic MCD in Ho3+ ion, but creates a condition for the appearance of a large paramagnetic MCD of mixing (B-term). With temperature increasing, the MCD spectrum of Ho3+ ion gradually turns into a spectrum typical for paramagnets with the predominance of the sign-changing diamagnetic part, because the influence of the exchange field decreases. The shape of the MCD spectra of Nd3+ ions are typical for paramagnets but does not change during the reorientation transition in the rest of the crystal. This means that the magnetic moment of the Nd3+ ion does not make a reorientation transition simultaneously with the Fe3+ and Ho3+ ions of the rest of the crystal. This phenomenon is accounted for by a strong local magnetic anisotropy of the Nd3+ ion and by a weak exchange interaction Fe-Nd, which is not enough for rotation of the Nd3+ ion moment synchronously with that of the Fe3+ ion. The magneto-optical properties of neodymium are controlled by the easy-axis anisotropy of neodymium.</div></div>\",\"PeriodicalId\":366,\"journal\":{\"name\":\"Journal of Magnetism and Magnetic Materials\",\"volume\":\"611 \",\"pages\":\"Article 172613\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-10-24\",\"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/S0304885324009041\",\"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/S0304885324009041","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}

引用次数: 0

摘要

研究了反铁磁性三棱晶体 Ho0.75Nd0.25Fe3(BO3)4 中 Ho3+ 离子的 5I8 → 5F2、5S2、5F3 和 5F5 吸收带区域以及 Nd3+ 离子的 4I9/2→4G7/2、2K13/2、4S3/2、4F7/2、4F5/2 和 2H9/2 吸收带区域的吸收光谱和磁圆二色性光谱（MCD）。在 TR = 6.9 К 的自旋定向转变过程中，Ho3+ 离子的 MCD 光谱形状发生了质的变化。在 TR 值以下，即晶体的易轴态，MCD 光谱具有典型的顺磁体形状，即由二磁性和顺磁性部分组成。就在 TR 的上方，在晶体的易面状态下，Ho3+ 离子的 MCD 具有与吸收光谱相似的光谱，这是 MCD 的顺磁部分的典型特征。研究表明，在易面状态下，铁的交换场垂直于沿 C3 轴方向的外场，淬灭了 Ho3+ 离子中通常的顺磁性和二磁性 MCD，但却为出现大的顺磁性混合 MCD（B 项）创造了条件。随着温度的升高，由于交换场的影响减小，Ho3+ 离子的 MCD 光谱逐渐变成了典型的顺磁体光谱，其中符号变化的二磁部分占主导地位。Nd3+ 离子的 MCD 光谱形状是典型的顺磁体，但在晶体其他部分的重新定向转变过程中并没有发生变化。这意味着 Nd3+ 离子的磁矩不会与晶体其余部分的 Fe3+ 和 Ho3+ 离子同时发生重新定向转变。造成这种现象的原因是 Nd3+ 离子具有很强的局部磁各向异性，而且 Fe-Nd 的交换相互作用很弱，不足以使 Nd3+ 离子的磁矩与 Fe3+ 离子的磁矩同步旋转。钕的磁光特性受钕的易轴各向异性控制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

查看原文本刊更多论文

Magnetic circular dichroism of f-f electron transitions in Ho3+ and Nd3+ ions in antiferromagnetic crystal Ho0.75Nd0.25Fe3(BO3)4 in the region of spin-reorientation transition

Absorption and magnetic circular dichroism (MCD) spectra have been studied in the region of ⁵I₈ → ⁵F₂, ⁵S₂, ⁵F₃, and ⁵F₅ absorption bands of the Ho³⁺ ion and in the region of ⁴I_9/2→⁴G_7/2, ²K_13/2, ⁴S_3/2, ⁴F_7/2, ⁴F_5/2 and ²H_9/2 absorption bands of the Nd³⁺ ion in an antiferromagnetic trigonal crystal Ho_0.75Nd_0.25Fe₃(BO₃)₄ in the temperature range from 5 to 90 K. A qualitative change in the shape of the MCD spectra of Ho³⁺ ion was revealed during the spin-reorientation transition at T_R = 6.9 К. Below T_R, in the easy-axis state of the crystal, the MCD spectrum has a shape typical for paramagnets, i.e., it consists of diamagnetic and paramagnetic parts. Just above T_R, in the easy-plane state of the crystal, MCD of Ho³⁺ ion has a spectrum similar to the absorption spectrum, which is typical for the paramagnetic part of the MCD. It was shown, that in the easy-plane state the exchange field of iron, being perpendicular to the external field directed along the C₃ axis, quenches the usual paramagnetic and diamagnetic MCD in Ho³⁺ ion, but creates a condition for the appearance of a large paramagnetic MCD of mixing (B-term). With temperature increasing, the MCD spectrum of Ho³⁺ ion gradually turns into a spectrum typical for paramagnets with the predominance of the sign-changing diamagnetic part, because the influence of the exchange field decreases. The shape of the MCD spectra of Nd³⁺ ions are typical for paramagnets but does not change during the reorientation transition in the rest of the crystal. This means that the magnetic moment of the Nd³⁺ ion does not make a reorientation transition simultaneously with the Fe³⁺ and Ho³⁺ ions of the rest of the crystal. This phenomenon is accounted for by a strong local magnetic anisotropy of the Nd³⁺ ion and by a weak exchange interaction Fe-Nd, which is not enough for rotation of the Nd³⁺ ion moment synchronously with that of the Fe³⁺ ion. The magneto-optical properties of neodymium are controlled by the easy-axis anisotropy of neodymium.

求助全文

通过发布文献求助，成功后即可免费获取论文全文。去求助

来源期刊

Journal of Magnetism and Magnetic Materials 物理-材料科学：综合

CiteScore

5.30

自引率

11.10%

发文量

1149

审稿时长

59 days

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.