Carrier-induced transition from antiferromagnetic insulator to ferromagnetic metal in the layered phosphide <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>EuZn</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">P</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Xiyu Chen, Wuzhang Yang, Jia-Yi Lu, Zhiyu Zhou, Zhi Ren, Guang‐Han Cao, Shuai Dong, Zhicheng Wang
Abstract
${\mathrm{EuZn}}_{2}{\mathrm{P}}_{2}$ was reported to be an insulating antiferromagnet with ${T}_{\mathrm{N}}$ of 23.5 K. In this study single crystals of ${\mathrm{EuZn}}_{2}{\mathrm{P}}_{2}$ exhibiting metallic behavior and a ferromagnetic order of 72 K (${T}_{\mathrm{C}}$) are successfully synthesized via a salt flux method. The presence of hole carriers induced by the Eu vacancies in the lattice is found to be crucial for the drastic changes in magnetism and electrical transport. The carriers mediate the interlayer ferromagnetic interaction, and the coupling strength is directly related to ${T}_{\mathrm{C}}$, as evidenced by the linear dependence of ${T}_{\mathrm{C}}$ and the fitted Curie-Weiss temperatures on the Eu-layer distances for ferromagnetic $\mathrm{Eu}{M}_{2}{X}_{2}$ ($M$ = Zn, Cd; $X$ = P, As). The ferromagnetic ${\mathrm{EuZn}}_{2}{\mathrm{P}}_{2}$ shows conspicuous negative magnetoresistance (MR) near ${T}_{\mathrm{C}}$ owing to strong magnetic scattering. The MR behavior is consistent with the Majumdar-Littlewood model, indicating that the MR can be enhanced by decreasing the carrier density. Our findings suggest that $\mathrm{Eu}{M}_{2}{X}_{2}$ has highly tunable magnetism and charge transport, making it a promising material family for potential applications in spintronics.