{"title":"基于电子顺磁共振和中子散射的MnSi自旋涨落跃迁","authors":"S. V. Demishev","doi":"10.1134/S1028335822100032","DOIUrl":null,"url":null,"abstract":"<p>The experimental data on low-temperature (<i>T</i> < 40 K) neutron scattering and electron paramagnetic resonance for a helical magnet manganese monosilicide (MnSi) are analyzed. It is established that the smooth evolution of the parameters of spin fluctuations considered both in the conventional theory of magnetic phase transitions and in its generalization to the case of helical magnets is disturbed by the presence of spin-fluctuation transitions (SFTs) in which the amplitude of spin fluctuations and their correlation radius change sharply. In a zero magnetic field, the transition at the temperature <i>T</i><sub>c</sub> = 29 K, which is usually interpreted as the transition to a helical magnetically ordered phase, is preceded by two spin-fluctuation transitions with <i>T</i><sub>1</sub> = 32 K and <i>T</i><sub>2</sub> = 30.5 K. In a magnetic field of <i>B</i> ~ 2 T at a temperature of 29 K coinciding with <i>T</i><sub>c</sub>, another spin-fluctuation transition with the parameters characteristic for the SFT inside the magnetically ordered phase is discovered. It is shown that, as the temperature decreases, MnSi at <i>T</i> = <i>T</i><sub>1</sub> undergoes the SFT with the appearance of helical fluctuations, while the appearance of a helical phase (<i>B</i> = 0) or a spin-polarized phase (<i>B</i> = 2 T) occurs at <i>T</i> = <i>T</i><sub>2</sub> and is accompanied by a spin-fluctuation transition.</p>","PeriodicalId":533,"journal":{"name":"Doklady Physics","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Spin-Fluctuation Transitions in MnSi According to Electron Paramagnetic Resonance and Neutron Scattering\",\"authors\":\"S. V. Demishev\",\"doi\":\"10.1134/S1028335822100032\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The experimental data on low-temperature (<i>T</i> < 40 K) neutron scattering and electron paramagnetic resonance for a helical magnet manganese monosilicide (MnSi) are analyzed. It is established that the smooth evolution of the parameters of spin fluctuations considered both in the conventional theory of magnetic phase transitions and in its generalization to the case of helical magnets is disturbed by the presence of spin-fluctuation transitions (SFTs) in which the amplitude of spin fluctuations and their correlation radius change sharply. In a zero magnetic field, the transition at the temperature <i>T</i><sub>c</sub> = 29 K, which is usually interpreted as the transition to a helical magnetically ordered phase, is preceded by two spin-fluctuation transitions with <i>T</i><sub>1</sub> = 32 K and <i>T</i><sub>2</sub> = 30.5 K. In a magnetic field of <i>B</i> ~ 2 T at a temperature of 29 K coinciding with <i>T</i><sub>c</sub>, another spin-fluctuation transition with the parameters characteristic for the SFT inside the magnetically ordered phase is discovered. It is shown that, as the temperature decreases, MnSi at <i>T</i> = <i>T</i><sub>1</sub> undergoes the SFT with the appearance of helical fluctuations, while the appearance of a helical phase (<i>B</i> = 0) or a spin-polarized phase (<i>B</i> = 2 T) occurs at <i>T</i> = <i>T</i><sub>2</sub> and is accompanied by a spin-fluctuation transition.</p>\",\"PeriodicalId\":533,\"journal\":{\"name\":\"Doklady Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2023-03-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Doklady Physics\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1134/S1028335822100032\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Doklady Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S1028335822100032","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MECHANICS","Score":null,"Total":0}
Spin-Fluctuation Transitions in MnSi According to Electron Paramagnetic Resonance and Neutron Scattering
The experimental data on low-temperature (T < 40 K) neutron scattering and electron paramagnetic resonance for a helical magnet manganese monosilicide (MnSi) are analyzed. It is established that the smooth evolution of the parameters of spin fluctuations considered both in the conventional theory of magnetic phase transitions and in its generalization to the case of helical magnets is disturbed by the presence of spin-fluctuation transitions (SFTs) in which the amplitude of spin fluctuations and their correlation radius change sharply. In a zero magnetic field, the transition at the temperature Tc = 29 K, which is usually interpreted as the transition to a helical magnetically ordered phase, is preceded by two spin-fluctuation transitions with T1 = 32 K and T2 = 30.5 K. In a magnetic field of B ~ 2 T at a temperature of 29 K coinciding with Tc, another spin-fluctuation transition with the parameters characteristic for the SFT inside the magnetically ordered phase is discovered. It is shown that, as the temperature decreases, MnSi at T = T1 undergoes the SFT with the appearance of helical fluctuations, while the appearance of a helical phase (B = 0) or a spin-polarized phase (B = 2 T) occurs at T = T2 and is accompanied by a spin-fluctuation transition.
期刊介绍:
Doklady Physics is a journal that publishes new research in physics of great significance. Initially the journal was a forum of the Russian Academy of Science and published only best contributions from Russia in the form of short articles. Now the journal welcomes submissions from any country in the English or Russian language. Every manuscript must be recommended by Russian or foreign members of the Russian Academy of Sciences.