Electron-lattice coupling and broken symmetries of the molecular salt(TMTTF)2SbF6
Electron-lattice coupling and broken symmetries of the molecular salt(TMTTF)2SbF6
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分子盐(TMTTF)2SbF6的电子晶格耦合和破缺对称性
DOI：
10.1103/physrevb.70.121101
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发表时间：
2004
影响因子：
3.7
通讯作者：
S. Brown
中科院分区：
文献类型：
--
作者：
W. Yu;F. Zhang;F. Zámborszky;B. Alavi;A. Baur;C. Merlic;S. Brown
用核磁共振谱测定了{(TMTTF})}{2}{(SBF)}{6}的温度/压力相图。在常压下，${T}_{\mathrm{CO}}=156\phantom{\rule{0.3em}{0ex}}\mathrm{K}$，发生了向电荷有序(CO)态的转变，在${T}_{N}=8\phantom{\rule{0.3em}{0ex}}\mathrm{K}$.下观察到了反铁磁(AF)有序当$Pg0.5\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$，没有CO的证据时，低温核磁共振谱符合单重态[Spin-Peierls(SP)]基态。在给定的压力下，CO有序参数的温度依赖关系不是单调的，这为确定哪些过程可能控制CO幅度提供了机会。核磁共振谱提供了电子-反离子耦合对稳定CO和AF相至关重要的经验证据。
The temperature/pressure phase diagram for ${(\mathrm{TMTTF})}_{2}{\mathrm{SbF}}_{6}$ is determined using $^{13}\mathrm{C}$ NMR spectroscopy. At ambient pressure, a transition to a charge-ordered (CO) state occurs at ${T}_{\mathrm{CO}}=156\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, and antiferromagnetic (AF) order is observed below ${T}_{N}=8\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Both are suppressed with pressure: when $Pg0.5\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$, there is no evidence for CO, and the low-temperature $^{13}\mathrm{C}$ NMR spectrum is consistent with a singlet [spin-Peierls (SP)] ground state. At a given pressure, the temperature dependence of the CO order parameter is not monotonic, and provides an opportunity to identify what processes could be controlling the CO amplitude. $^{19}\mathrm{F}$ NMR spectroscopy provides empirical evidence that electron-counterion coupling is crucial to stabilizing the CO and AF phases.