Electronic properties of the dimerized organic conductor $κ$-(BETS)$_2$Mn[N(CN)$_2$]$_3$

Marvin Schmidt, Savita Priya, Zhijie Huang, Mark Kartsovnik, Natalia Kushch, Martin Dressel
{"title":"Electronic properties of the dimerized organic conductor $κ$-(BETS)$_2$Mn[N(CN)$_2$]$_3$","authors":"Marvin Schmidt, Savita Priya, Zhijie Huang, Mark Kartsovnik, Natalia Kushch, Martin Dressel","doi":"arxiv-2409.08656","DOIUrl":null,"url":null,"abstract":"The two-dimensional molecular conductor $\\kappa$-(BETS)$_2$Mn[N(CN)$_2$]$_3$\nundergoes a sharp metal-to-insulator phase transition at $T_{\\rm MI}\\approx$ 21\nK, which has been under scrutiny for many years. We have performed\ncomprehensive infrared investigations along the three crystallographic\ndirections as a function of temperature down to 10 K, complemented by electron\nspin resonance and dc-transport studies. The in-plane anisotropy of the optical\nconductivity is more pronounced than in any other $\\kappa$-type BEDT-TTF or\nrelated compounds. The metal-insulator transitions affects the molecular\nvibrations due to the coupling to the electronic system; in addition we observe\na clear splitting of the charge-sensitive vibrational modes below $T_{\\rm MI}$\nthat evidences the presence of two distinct BETS dimers in this compound. The\nMn[N(CN)$_2$]$_3^-$ layers are determined by the chain structure of the anions\nresulting in a rather anisotropic behavior and remarkable temperature\ndependence of the vibronic features. At low temperatures the ESR properties are\naffected by the Mn$^{2+}$ ions via $\\pi$-$d$-coupling and antiferromagnetic\nordering within the $\\pi$-spins: The $g$-factor shifts enormously with a\npronounced in-plane anisotropy that flips as the temperature decreases; the\nlines broaden significantly; and the spin susceptibility increases upon cooling\nwith a kink at the phase transition.","PeriodicalId":501171,"journal":{"name":"arXiv - PHYS - Strongly Correlated Electrons","volume":"47 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Strongly Correlated Electrons","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.08656","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

The two-dimensional molecular conductor $\kappa$-(BETS)$_2$Mn[N(CN)$_2$]$_3$ undergoes a sharp metal-to-insulator phase transition at $T_{\rm MI}\approx$ 21 K, which has been under scrutiny for many years. We have performed comprehensive infrared investigations along the three crystallographic directions as a function of temperature down to 10 K, complemented by electron spin resonance and dc-transport studies. The in-plane anisotropy of the optical conductivity is more pronounced than in any other $\kappa$-type BEDT-TTF or related compounds. The metal-insulator transitions affects the molecular vibrations due to the coupling to the electronic system; in addition we observe a clear splitting of the charge-sensitive vibrational modes below $T_{\rm MI}$ that evidences the presence of two distinct BETS dimers in this compound. The Mn[N(CN)$_2$]$_3^-$ layers are determined by the chain structure of the anions resulting in a rather anisotropic behavior and remarkable temperature dependence of the vibronic features. At low temperatures the ESR properties are affected by the Mn$^{2+}$ ions via $\pi$-$d$-coupling and antiferromagnetic ordering within the $\pi$-spins: The $g$-factor shifts enormously with a pronounced in-plane anisotropy that flips as the temperature decreases; the lines broaden significantly; and the spin susceptibility increases upon cooling with a kink at the phase transition.
二聚化有机导体 $κ$-(BETS)$_2$Mn[N(CN)$_2$]$_3$ 的电子特性
二维分子导体$\kappa$-(BETS)$_2$Mn[N(CN)$_2$]$_3$在$T_{\rm MI}\approx$21K时发生了急剧的金属-绝缘体相变,多年来一直受到人们的关注。我们沿着低至 10 K 的温度函数的三个晶体学方向进行了全面的红外研究,并辅以电子自旋共振和直流传输研究。与其他 $\kappa$ 型 BEDT-TTF 或相关化合物相比,光导率的面内各向异性更为明显。由于与电子系统的耦合,金属-绝缘体转变会影响分子振动;此外,我们还观察到电荷敏感振动模式在 $T_{\rm MI}$ 以下有明显的分裂,这证明该化合物中存在两种不同的 BETS 二聚体。锰[N(CN)$_2$]$_3^-$层是由阴离子的链结构决定的,这导致了其各向异性的行为和振动特征的显著温度依赖性。在低温条件下,Mn$^{2+}$ 离子通过$\pi$-$d$耦合和$\pi$-spins 内的反铁磁排序影响 ESR 特性:随着温度的降低,面内各向异性会发生明显的翻转,从而使 g 因子发生巨大的变化;自旋线会显著变宽;冷却时自旋易感性会增加,并在相变处出现扭结。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信