Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker
{"title":"单晶反铁磁性 Mn2Au 中的磁各向异性","authors":"Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker","doi":"10.1103/physrevmaterials.8.084413","DOIUrl":null,"url":null,"abstract":"Multiple recent studies have identified the metallic antiferromagnet <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals precipitate below <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>550</mn><msup><mspace width=\"0.16em\"></mspace><mo>∘</mo></msup><mi mathvariant=\"normal\">C</mi></mrow></math>, about <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>100</mn><msup><mspace width=\"0.16em\"></mspace><mo>∘</mo></msup><mi mathvariant=\"normal\">C</mi></mrow></math> below the decomposition temperature of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>. Bulk <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a room-temperature resistivity of 16–19 <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>µ</mi><mi mathvariant=\"normal\">Ω</mi><mspace width=\"0.16em\"></mspace><mi>cm</mi></mrow></math> and a residual resistivity ratio of 41. <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a dimensionless susceptibility on the order of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> constrains the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane magnetic susceptibility to be constant, meaning that <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>χ</mi><mn>100</mn></msub><mo>=</mo><msub><mi>χ</mi><mn>110</mn></msub></mrow></math> in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>χ</mi><mn>100</mn></msub><mo>,</mo><mo> </mo><msub><mi>χ</mi><mn>110</mn></msub></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>χ</mi><mn>001</mn></msub></math> are the same order of magnitude and agree with the calculated prediction, meaning the low-field susceptibility of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> is quite isotropic, despite clear differences in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>a</mi><mi>c</mi></mrow></math>-plane magnetocrystalline anisotropy. <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> is calculated to have an extremely high in-plane spin-flop field above 30 T, which is much larger than that of another in-plane antiferromagnet, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi>As</mi></mrow></math> (less than 1 T). The subtle anisotropy of intrinsic susceptibilities may lead to dominating effects from shape, crystalline texture, strain, and defects in devices that attempt spin readout in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>.","PeriodicalId":20545,"journal":{"name":"Physical Review Materials","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Magnetic anisotropy in single-crystalline antiferromagnetic Mn2Au\",\"authors\":\"Mebatsion S. Gebre, Rebecca K. Banner, Kisung Kang, Kejian Qu, Huibo Cao, André Schleife, Daniel P. Shoemaker\",\"doi\":\"10.1103/physrevmaterials.8.084413\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Multiple recent studies have identified the metallic antiferromagnet <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals precipitate below <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>550</mn><msup><mspace width=\\\"0.16em\\\"></mspace><mo>∘</mo></msup><mi mathvariant=\\\"normal\\\">C</mi></mrow></math>, about <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>100</mn><msup><mspace width=\\\"0.16em\\\"></mspace><mo>∘</mo></msup><mi mathvariant=\\\"normal\\\">C</mi></mrow></math> below the decomposition temperature of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>. Bulk <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a room-temperature resistivity of 16–19 <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mi>µ</mi><mi mathvariant=\\\"normal\\\">Ω</mi><mspace width=\\\"0.16em\\\"></mspace><mi>cm</mi></mrow></math> and a residual resistivity ratio of 41. <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> crystals have a dimensionless susceptibility on the order of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> constrains the <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane magnetic susceptibility to be constant, meaning that <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>χ</mi><mn>100</mn></msub><mo>=</mo><msub><mi>χ</mi><mn>110</mn></msub></mrow></math> in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>χ</mi><mn>100</mn></msub><mo>,</mo><mo> </mo><msub><mi>χ</mi><mn>110</mn></msub></math>, and <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>χ</mi><mn>001</mn></msub></math> are the same order of magnitude and agree with the calculated prediction, meaning the low-field susceptibility of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> is quite isotropic, despite clear differences in <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mi>a</mi><mi>b</mi></mrow></math>-plane and <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mi>a</mi><mi>c</mi></mrow></math>-plane magnetocrystalline anisotropy. <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math> is calculated to have an extremely high in-plane spin-flop field above 30 T, which is much larger than that of another in-plane antiferromagnet, <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Fe</mi><mn>2</mn></msub><mi>As</mi></mrow></math> (less than 1 T). The subtle anisotropy of intrinsic susceptibilities may lead to dominating effects from shape, crystalline texture, strain, and defects in devices that attempt spin readout in <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>Mn</mi><mn>2</mn></msub><mi>Au</mi></mrow></math>.\",\"PeriodicalId\":20545,\"journal\":{\"name\":\"Physical Review Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.1000,\"publicationDate\":\"2024-08-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Review Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://doi.org/10.1103/physrevmaterials.8.084413\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1103/physrevmaterials.8.084413","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Magnetic anisotropy in single-crystalline antiferromagnetic Mn2Au
Multiple recent studies have identified the metallic antiferromagnet to be a candidate for spintronic applications due to apparent in-plane anisotropy, preserved magnetic properties above room temperature, and current-induced Néel vector switching. Crystal growth is complicated by the fact that melts incongruently. We present a bismuth flux method to grow millimeter-scale bulk single crystals of in order to examine the intrinsic anisotropic electrical and magnetic properties. Flux quenching experiments reveal that the crystals precipitate below , about below the decomposition temperature of . Bulk crystals have a room-temperature resistivity of 16–19 and a residual resistivity ratio of 41. crystals have a dimensionless susceptibility on the order of (SI units), comparable to calculated and experimental reports on powder samples. Single-crystal neutron diffraction confirms the in-plane magnetic structure. The tetragonal symmetry of constrains the -plane magnetic susceptibility to be constant, meaning that in the low-field limit, below any spin-flop transition. We find that three measured magnetic susceptibilities , and are the same order of magnitude and agree with the calculated prediction, meaning the low-field susceptibility of is quite isotropic, despite clear differences in -plane and -plane magnetocrystalline anisotropy. is calculated to have an extremely high in-plane spin-flop field above 30 T, which is much larger than that of another in-plane antiferromagnet, (less than 1 T). The subtle anisotropy of intrinsic susceptibilities may lead to dominating effects from shape, crystalline texture, strain, and defects in devices that attempt spin readout in .
期刊介绍:
Physical Review Materials is a new broad-scope international journal for the multidisciplinary community engaged in research on materials. It is intended to fill a gap in the family of existing Physical Review journals that publish materials research. This field has grown rapidly in recent years and is increasingly being carried out in a way that transcends conventional subject boundaries. The journal was created to provide a common publication and reference source to the expanding community of physicists, materials scientists, chemists, engineers, and researchers in related disciplines that carry out high-quality original research in materials. It will share the same commitment to the high quality expected of all APS publications.