Spin-flip-driven giant magnetotransport in A-type antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>NaCr</mml:mi><mml:msub><mml:mi>Te</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Junjie Wang, Jun Deng, Xiaowei Liang, Guoying Gao, Tianping Ying, Shangjie Tian, Hechang Lei, Yanpeng Song, Chen Xu, Jiangang Guo, Xiaolong Chen
Abstract
The value of angle-dependent magnetoresistance (MR) synergistically and simultaneously depends on the magnitudes of magnetoresistance (MR) and magnetocrystalline anisotropy energy (MAE). In a magnetic material, the concurrence of gigantic angle-dependent MR and MR signals is rather difficult due to weak spin-lattice coupling and small MAE. Here we report the considerable magnetotransport effect in layered A-type antiferromagnetic (AFM) $\mathrm{NaCr}{\mathrm{Te}}_{2}$ by realigning the spin configurations. Above 3 (8) T, the antiparallel spins of adjacent layers experience a spin-flip transition to a parallel alignment along the $c$ axis ($ab$ plane). Theoretical calculations reveal that the energy band gap narrows from 0.39 to 0.11 eV, accompanying a transition from semiconductor (high-$R$ state) and half semiconductor (low-$R$ state), respectively. Thus, a gigantic negative MR ratio of \ensuremath{-}90% is obtained at 10 K. More importantly, the decrement of $R$ along $H\ensuremath{\parallel}c$ is far quicker than that of $H\ensuremath{\parallel}ab$ because the MAE of the Ising-like ferromagnetic (FM) state is $1017\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{eV}/{\mathrm{Cr}}^{3+}$ lower than that of XY-like FM. The distinct trends result in the angle-dependent MR ratio of 732% at 10 K. These findings unravel the intrinsic origin of magnetoresistance in $\mathrm{NaCr}{\mathrm{Te}}_{2}$ and will stimulate us to explore the $H$-sensitive transport property in more AFM materials.