Elevating the magnetic exchange coupling in the compressed antiferromagnetic axion insulator candidate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Eu</mml:mi><mml:msub><mml:mi>In</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>As</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Fanghang Yu, Haimen Mu, Weizhuang Zhuo, Zhenyu Wang, Z. F. Wang, Jianjun Ying, Xianhui Chen
Abstract
The magnetic topological materials have attracted much attention recently for their potential realization of various novel quantum states. However, the onset of magnetization in these materials usually occurs at low temperatures, impeding further applications. Here, by means of high pressure, we have significantly increased the magnetic transition temperature in an antiferromagnetic axion insulator candidate $\mathrm{Eu}{\mathrm{In}}_{2}{\mathrm{As}}_{2}$. Both crystal and magnetic structures remain the same with pressure up to 17 GPa. The N\'eel temperature can be monotonously increased from 16 K (ambient pressure) to 65 K (14.7 GPa). This is mainly attributed to the enhancement of intralayer ferromagnetic exchange coupling by pressure. With increasing pressure up to 17 GPa, a crystalline-to-amorphous phase transition occurs, which impedes further enhancement of the N\'eel temperature. Our results show that high pressure is an effective pathway to greatly enhance the magnetic transition temperature in topological materials. It is helpful for the realization of novel quantum states at elevated temperatures.