(^{133}\)Cs and \(^{75}\)As NMR investigation of the normal metallic state of the quasi-one-dimensional Cs\(_2\)Cr\(_3\)As\(_3\)

• Published in: arXiv.org 2016-05
• Main Authors: Haizhao Zhi, Imai, Takashi, Tang, Zhangtu, Liu, Yi, Cao, Guanghan
• Format: Article
• Language: English
• Subjects: Cesium; Chromium; Electrical conduction; NMR; Nuclear magnetic resonance; Nuclear quadrupole resonance; Nuclear spin; Quadrupoles; Rubidium; Spin dynamics; Spin-lattice relaxation; Variations
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1605.04347

We report \(^{133}\)Cs NMR and \(^{75}\)As Nuclear Quadrupole Resonance (NQR) measurements on the normal metallic state above \(T_c\) of a quasi-one-dimensional superconductor Cs\(_2\)Cr\(_3\)As\(_3\) (\(T_c < 1.6\)~K). From the \(^{133}\)Cs NMR Knight shift \(^{133}K\) measured at the Cs1 site, we show that the uniform spin susceptibility \(\chi_{spin}\) increases from 295~K to \(\sim\) 60~K, followed by a mild suppression; \(\chi_{spin}\) then levels off below \(\sim\)10~K. In contrast, a vanishingly small magnitude of \(^{133}K\) indicates that Cs2 sites contribute very little to electrical conduction and the exchange interactions between 3d electrons at Cr sites. Low frequency Cr spin dynamics, reflected on \(^{75}\)As \(1/T_1T\) (the nuclear spin-lattice relaxation rate \(1/T_1\) divided by temperature \(T\)), shows an analogous trend as \(\chi_{spin}\). Comparison with the results of \(1/T_1T\) near \(T_c\) with Rb\(_2\)Cr\(_3\)As\(_3\) (\(T_c=6.1\)~K) and Rb\(_2\)Cr\(_3\)As\(_3\) (\(T_c=4.8\)~K) establishes a systematic trend that substitution of K\(^{+}\) ions with larger alkali ions progressively suppresses Cr spin fluctuations together with \(T_c\).