螺旋磁性
外觀
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0d/FeGe_magnetic_phase_diagram2b.png/220px-FeGe_magnetic_phase_diagram2b.png)
螺旋磁性是一種相鄰磁矩的自旋以螺旋模式進行排列的磁序形式,其特徵轉角介於0到180度之間。這種現象是鐵磁和反鐵磁交換相互作用之間競爭的結果,也可以分別將鐵磁和反鐵磁視為具有0度和180度特徵轉角的螺旋磁結構。螺旋磁序本質上可以是左旋或右旋的,因此螺旋磁序破壞了空間反演對稱性。
嚴格來說,螺旋磁體並沒有永久磁矩,因此有時被認為是一種複雜的反鐵磁體。而錐形磁性除了具有螺旋調製外還有永久磁矩(例如,金屬鈥在低於20K時表現出錐形磁性[1])。是否具有永久磁矩可以將螺旋磁體與錐形磁體區分開來。
螺旋磁性的概念於1959年首次提出,它可以作為對二氧化錳磁結構的解釋[2]。螺旋磁性最初應用於中子衍射,後來發現它可以被洛倫茲電子顯微鏡更直接地觀察到[3]。據報道,大部分材料在低溫下表現出螺旋磁性,然而也有一些螺旋磁結構可以在室溫下保持穩定[4]。許多螺旋磁體具有手性立方結構,例如B20晶體結構類型。
就像普通鐵磁體具有分隔各個磁疇的疇壁一樣,螺旋磁體也有自己的以拓撲電荷為特徵的疇壁。 [5]
材料 | 溫度範圍 |
---|---|
β-MnO2 [2][6] | < 93 K |
FeGe, [4] | < 278 K |
MnGe[7] | < 170 K |
MnSi, [8] | < 29 K |
FexCo1−xSi (0.3 ≤ x ≤ 0.85) [9] [10] | |
Cu2OSeO3[11] | < 58 K |
Tb[12] | 219–231 K |
Dy[13] | 85–179 K |
Ho[14] | 20–132 K |
參見
[編輯]參考文獻
[編輯]- ^ Perreault, Christopher S.; Vohra, Yogesh K.; dos Santos, Antonio M.; Molaison, Jamie J. Neutron diffraction study of magnetic ordering in high pressure phases of rare earth metal holmium. Journal of Magnetism and Magnetic Materials (Elsevier BV). 2020, 507: 166843. Bibcode:2020JMMM..50766843P. OSTI 1607351. doi:10.1016/j.jmmm.2020.166843.
- ^ 2.0 2.1 Yoshimori, Akio. A New Type of Antiferromagnetic Structure in the Rutile Type Crystal. Journal of the Physical Society of Japan (Physical Society of Japan). 1959, 14 (6): 807–821. Bibcode:1959JPSJ...14..807Y. doi:10.1143/jpsj.14.807.
- ^ Uchida, Masaya; Onose, Yoshinori; Matsui, Yoshio; Tokura, Yoshinori. Real-Space Observation of Helical Spin Order. Science (American Association for the Advancement of Science (AAAS)). 2006, 311 (5759): 359–361. Bibcode:2006Sci...311..359U. PMID 16424334. doi:10.1126/science.1120639.
- ^ 4.0 4.1 Zhang, S. L.; Stasinopoulos, I.; Lancaster, T.; Xiao, F.; Bauer, A.; et al. Room-temperature helimagnetism in FeGe thin films. Scientific Reports (Springer Science and Business Media LLC). 2017, 7 (1): 123. Bibcode:2017NatSR...7..123Z. PMC 5427977
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- ^ Schoenherr, P.; Müller, J.; Köhler, L.; Rosch, A.; Kanazawa, N.; Tokura, Y.; Garst, M.; Meier, D. Topological domain walls in helimagnets. Nature Physics (Springer Science and Business Media LLC). 2018, 14 (5): 465–468. Bibcode:2018NatPh..14..465S. arXiv:1704.06288
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- ^ Regulski, M.; Przeniosło, R.; Sosnowska, I.; Hoffmann, J.-U. Incommensurate magnetic structure of β−MnO2. Physical Review B (American Physical Society (APS)). 2003-11-03, 68 (17): 172401. ISSN 0163-1829. doi:10.1103/physrevb.68.172401.
- ^ Martin, N.; Mirebeau, I.; Franz, C.; Chaboussant, G.; Fomicheva, L. N.; Tsvyashchenko, A. V. Partial ordering and phase elasticity in the MnGe short-period helimagnet (PDF). Physical Review B (American Physical Society (APS)). 2019-03-13, 99 (10): 100402(R) [2021-09-26]. Bibcode:2019PhRvB..99j0402M. ISSN 2469-9950. doi:10.1103/physrevb.99.100402. (原始內容存檔 (PDF)於2021-12-30).
- ^ Stishov, Sergei M; Petrova, A E. Itinerant helimagnet MnSi. Physics-Uspekhi (Uspekhi Fizicheskikh Nauk (UFN) Journal). 2011-11-30, 54 (11): 1117–1130. Bibcode:2011PhyU...54.1117S. doi:10.3367/ufne.0181.201111b.1157.
- ^ Watanabe, Hideki; Tazuke, ichi; Nakajima, Haruo. Helical Spin Resonance and Magntization Measurement in Itinerant Helimagnet FexCo1−xSi (0.3≤x≤0.85). Journal of the Physical Society of Japan (Physical Society of Japan). 1985, 54 (10): 3978–3986. Bibcode:1985JPSJ...54.3978W. doi:10.1143/jpsj.54.3978.
- ^ Bannenberg, L. J.; Kakurai, K.; Falus, P.; Lelièvre-Berna, E.; Dalgliesh, R.; et al. Universality of the helimagnetic transition in cubic chiral magnets: Small angle neutron scattering and neutron spin echo spectroscopy studies of FeCoSi. Physical Review B. 2017, 95 (14): 144433. Bibcode:2017PhRvB..95n4433B. arXiv:1701.05448
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- ^ Palmer, S. B.; Baruchel, J.; Farrant, S.; Jones, D.; Schlenker, M. Observation of Spiral Spin Antiferromagnetic Domains in Single Crystal Terbium. Boston, MA: Springer US. 1982: 413–417. ISBN 978-1-4613-3408-8. doi:10.1007/978-1-4613-3406-4_88.
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