Cs133 and As75 NMR investigation of the normal metallic state of quasi-one-dimensional Cs2Cr3As3
Year: 2016
Type: article
Abstract: We report $^{133}\mathrm{Cs}$ NMR and $^{75}\mathrm{As}$ nuclear quadrupole resonance (NQR) measurements on the normal metallic state above ${T}_{c}$ of a quasi-one-dimensional superconductor ${\mathrm{Cs}}_{2}{\mathrm{Cr}}_{3}{\mathrm{As}}_{3}$ (${T}_{c}<1.6$ K). From the $^{133}\mathrm{Cs}$ NMR Knight shift $^{133}K$ measured at the Cs1 site, we show that the uniform spin susceptibility ${\ensuremath{\chi}}_{\mathrm{spin}}$ increases from 295 K to $\ensuremath{\sim}60$ K, followed by a mild suppression; ${\ensuremath{\chi}}_{\mathrm{spin}}$ then levels off below $\ensuremath{\sim}10$ 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 $^{75}\mathrm{As}\phantom{\rule{4pt}{0ex}}1/{T}_{1}T$ (the nuclear spin-lattice relaxation rate $1/{T}_{1}$ divided by temperature $T$), shows an analogous trend as ${\ensuremath{\chi}}_{\mathrm{spin}}$. Comparison with the results of $1/{T}_{1}T$ near ${T}_{c}$ with ${\mathrm{K}}_{2}{\mathrm{Cr}}_{3}{\mathrm{As}}_{3}$ (${T}_{c}=6.1$ K) and ${\mathrm{Rb}}_{2}{\mathrm{Cr}}_{3}{\mathrm{As}}_{3}$ (${T}_{c}=4.8$ K) establishes a systematic trend that substitution of ${\mathrm{K}}^{+}$ ions with larger alkali ions progressively suppresses Cr spin fluctuations together with ${T}_{c}$.
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1149947311, G3483678011
OpenAlex ID: W2394532728