Enhancement of superconductivity and suppression of charge-density wave in As-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>CsV</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mi>Sb</mml:mi><mml:mn>5</mml:mn></mml:msub></mml:mrow></mml:math>
Yi Liu, Chang-Chao Liu, Qinqing Zhu, Liang‐Wen Ji, Siqi Wu, Yun‐Lei Sun, Jin‐Ke Bao, Wen‐He Jiao, Xiaofeng Xu, Zhi Ren, Guang‐Han Cao
Abstract
We have investigated the As-doping effect in the newly discovered kagome superconductor ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ via measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and specific heat. Our results show that partial substitution of Sb with As leads to shrinkage of the $c$ lattice, which effectively applies a chemical pressure in the system. The solubility of As atoms is about $2.3%$ for single crystals grown by the self-flux method. In the As-doped single crystal ${\mathrm{CsV}}_{3}{({\mathrm{Sb}}_{0.977}{\mathrm{As}}_{0.023})}_{5}$, the charge-density-wave (CDW) transition temperature ${T}_{\mathrm{CDW}}$ is suppressed from 94 to 83 K, and the superconducting transition temperature ${T}_{\mathrm{c}}$ is enhanced from 2.5 to 3.6 K. Furthermore, the residual resistivity ratio is significantly reduced, and the magnetoresistance with magnetic field along the $c$ axis decreases by nearly one order of magnitude, indicating substantial disorder scattering induced by the As doping. The anomalous Hall effect (AHE) is only observed below ${T}_{\mathrm{CDW}}$, indicating the intimate relationship between CDW and AHE. We found that the As-doping effect on ${T}_{\mathrm{c}}$ and ${T}_{\mathrm{CDW}}$ is basically equivalent to the hydrostatic pressure effect at 0.2 GPa.