Anomalous electrical transport and magnetic skyrmions in Mn-tuned Co9Zn9Mn2 single crystals

TL;DR

This study reports the growth and analysis of Mn-tuned Co9Zn9Mn2 single crystals, revealing skyrmion phases and anomalous electrical transport properties, including negative magnetoresistance and intrinsic Hall effects, relevant for spintronic applications.

Contribution

First systematic investigation of magnetic and transport properties of Mn-tuned Co9Zn9Mn2 single crystals, highlighting skyrmion phases and anomalous Hall effects in these alloys.

Findings

Skyrmion phase exists just below Curie temperature.

Negative linear magnetoresistance observed from 2 K to 380 K.

Intrinsic mechanism dominates anomalous Hall effect.

Abstract

\b{eta}-Mn-type CoxZnyMnz (x + y + z = 20) alloys have recently attracted increasing attention as a new 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 \b{eta}-Mn-type Co9.24Zn9.25Mn1.51 and Co9.02Zn9.18Mn1.80 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 from 2 K to 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 Co9.24Zn9.25Mn1.51 and Co9.02Zn9.18Mn1.80 single crystals is dominated by the intrinsic mechanism. Our findings contribute to a deeper understanding of the properties of CoxZnyMnz (x + y + z = 20) alloys material and advance their application in spintronic devices.