Manipulating magnetism and transport properties of EuCd$_2$P$_2$ with a low carrier concentration

TL;DR

This study demonstrates how EuCd₂P₂'s magnetic and electronic properties can be effectively tuned by adjusting carrier concentration, transforming it from an antiferromagnet with colossal magnetoresistance to a ferromagnet with metallic behavior, relevant for spintronics.

Contribution

It reveals the controllability of EuCd₂P₂'s magnetic states through low carrier concentration manipulation, combining experimental and theoretical insights.

Findings

EuCd₂P₂ transitions from antiferromagnetic to ferromagnetic with increased carrier density.

Low hole concentration of 10^{19} cm^{-3} induces significant magnetic and transport changes.

Field-effect control of carrier density can switch magnetic states in EuCd₂P₂.

Abstract

Materials that exhibit strongly coupled magnetic order and electronic properties are crucial for both fundamental research and technological applications. However, finding a material that not only shows remarkable magnetoresistive responses but also has an easily tunable ground state remains a challenge. Here, we report successful manipulation of the magnetic and transport properties of EuCd$_2$P$_2$, which is transformed from an A-type antiferromagnet ($T_\mathrm{N}$ = 11 K) exhibiting colossal magnetoresistance into a ferromagnet ($T_\mathrm{C}$ = 47 K) with metallic behavior. The dramatic alteration results from a low hole concentration of $10^{19}$ cm$^{-3}$ induced by changing the growth conditions. Electronic structure and total energy calculations confirm the tunability of magnetism with a small carrier concentration for EuCd$_2$P$_2$. It is feasible to switch between the magnetic states by using field-effect to control the carrier density, thereby changing the magneto-electronic response. The controllable magnetism and electrical transport of EuCd$_2$P$_2$ make it a potential candidate for spintronics.