论文标题
通过NMR和NQR参数的F-Doped Lafeaso的统一相图
A unified phase diagram of F-doped LaFeAsO by means of NMR and NQR parameters
论文作者
论文摘要
我们将$^{75} $作为核磁和四极共振结果（NMR，NQR），上面是一组新的LaFeaso $ _ {1-x} $ f $ _x $ _x $ polycrystalline样品。改善的合成条件导致更均质的样品，并更好地控制氟含量。结构性$ \ equiv $ nematic，磁性和超导过渡温度已通过NMR自旋晶格松弛率和AC敏感性测量确定。所谓的相图偏离了已发表的相位图，尤其是对于低F掺杂浓度而言。但是，如果从NQR光谱确定掺杂水平，则可以对两个相图进行核对。已经证实了磁性和超导性的散装共存以及纳米级分离为低兴奋剂样和高兴奋剂样区域。在磁性和超导性边界处于不足的样品上的其他频率依赖性强度，自旋旋转和自旋晶格弛豫率测量表明，正交性和磁性源自低掺杂的区域，并且超导性在高兴奋的类似区域的首次发展。
We present $^{75}$As Nuclear Magnetic and Quadrupole Resonance results (NMR, NQR) on a new set of LaFeAsO$_{1-x}$F$_x$ polycrystalline samples. Improved synthesis conditions led to more homogenized samples with better control of the fluorine content. The structural$\equiv$nematic, magnetic, and superconducting transition temperatures have been determined by NMR spin-lattice relaxation rate and AC susceptibility measurements. The so-determined phase diagram deviates from the published one especially for low F-doping concentrations. However, if the doping level is determined from the NQR spectra, both phase diagrams can be reconciled. The absence of bulk coexistence of magnetism and superconductivity and a nanoscale separation into low-doping-like and high-doping-like regions have been confirmed. Additional frequency dependent intensity, spin-spin, and spin-lattice relaxation rate measurements on underdoped samples at the boundary of magnetism and superconductivity indicate that orthorhombicity and magnetism originate from the low-doping-like regions, and superconductivity develops at first in the high-doping-like regions.
