Anomalous electrical transport and magnetic skyrmions in Mn-tuned <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Co</mml:mi><mml:mn>9</mml:mn></mml:msub><mml:msub><mml:mi>Zn</mml:mi><mml:mn>9</mml:mn></mml:msub><mml:msub><mml:mi>Mn</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> single crystals
Fangyi Qi, Yalei Huang, Xinyu Yao, Wenlai Lu, Guixin Cao
Abstract
\ensuremath{\beta}-Mn-type ${\mathrm{Co}}_{x}{\mathrm{Zn}}_{y}{\mathrm{Mn}}_{z}$ $(x+y+z=20)$ alloys have recently attracted increasing attention as a class of chiral magnets with skyrmions at and above room temperature. However, experimental studies on the transport properties of this material are scarce. In this work, we report the successful growth of the \ensuremath{\beta}-Mn-type ${\mathrm{Co}}_{9.24}{\mathrm{Zn}}_{9.25}{\mathrm{Mn}}_{1.51}$ and ${\mathrm{Co}}_{9.02}{\mathrm{Zn}}_{9.18}{\mathrm{Mn}}_{1.80}$ single crystals and a systematic study on their magnetic and transport properties. The skyrmion phase was found in a small temperature range just below the Curie temperature. The isothermal ac susceptibility and dc magnetization as a function of magnetic field confirm the existence of the skyrmion phase. A negative linear magnetoresistance over a wide temperature range 2--380 K is observed and attributed to the suppression of the magnetic ordering fluctuation under high fields. Both the magnetization and electrical resistivity are almost isotropic. The quantitative analysis of the Hall resistance suggests that the anomalous Hall effect of ${\mathrm{Co}}_{9.24}{\mathrm{Zn}}_{9.25}{\mathrm{Mn}}_{1.51}$ and ${\mathrm{Co}}_{9.02}{\mathrm{Zn}}_{9.18}{\mathrm{Mn}}_{1.80}$ single crystals is dominated by the intrinsic mechanism. Our findings contribute to a deeper understanding of the transport properties of ${\mathrm{Co}}_{x}{\mathrm{Zn}}_{y}{\mathrm{Mn}}_{z}$ $(x+y+z=20)$ alloys material and advance their application in spintronic devices.