Strain-controlled switch between ferromagnetism and antiferromagnetism in 1T-CrX2 (X = Se, Te) monolayers
Strain-controlled switch between ferromagnetism and antiferromagnetism in 1T-CrX2 (X = Se, Te) monolayers
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1T-CrX2 (X = Se, Te) 单层中铁磁性和反铁磁性之间的应变控制转换
DOI：
10.1103/physrevb.92.214419
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发表时间：
2015-12-14
影响因子：
3.7
通讯作者：
Sun, Y. P.
中科院分区：
文献类型：
--
作者：
Lv, H. Y.;Lu, W. J.;Sun, Y. P.
本文报道了基于第一性原理计算的1 T-CrX_2（X = Se，Te）单分子膜中铁磁（FM）和反铁磁（AFM）有序之间的应变诱导开关。没有应变的CrSe_2和CrTe_2单分子膜分别为AFM和FM。在双向拉伸应变下，当应变大于2%时，CrSe 2单层膜趋于FM。当应变增加时，FM状态进一步稳定。此外，当拉伸应变大于10%时，CrSe 2单层变为半金属，而对于CrTe 2单层，在FM和AFM状态之间发生转变的临界应变是压缩的，为-1%。4%和2%的相对小的拉伸应变，分别可以提高居里温度的CrSe 2和CrTe 2单层高于室温。CrSe_2（CrTe_2）单分子膜中FM态和AFM态之间的应变诱导转换可以通过AFM Cr-Cr直接交换相互作用和FM Cr-Se（Te）-Cr超交换相互作用之间的竞争来理解。由柔性应变控制的可调谐和有吸引力的磁性和电子性质对于未来的纳米电子应用是期望的。
We report on the strain-induced switch between ferromagnetic (FM) and antiferromagnetic (AFM) orderings in 1T-CrX2 (X = Se, Te) monolayers based on first-principles calculations. The CrSe2 and CrTe2 monolayers without strains are found to be AFM and FM, respectively. Under biaxial tensile strain, the CrSe2 monolayer tends to be FM when the strain is larger than 2%. The FM state is further stabilized when the strain is increased. Moreover, the CrSe2 monolayer becomes half metallic when the tensile strain is larger than 10%, while for the CrTe2 monolayer, the critical strain at which the transition between the FM and AFM states occurs is compressive, of -1%. Relatively small tensile strains of 4% and 2%, respectively, can enhance the Curie temperature of the CrSe2 and CrTe2 monolayers above room temperature. The strain-induced switch between the FM and AFM states in a CrSe2 (CrTe2) monolayer can be understood by the competition between the AFM Cr-Cr direct exchange interaction and the FM Cr-Se(Te)-Cr superexchange interaction. Tunable and attractive magnetic and electronic properties controlled by flexible strain are desirable for future nanoelectronic applications.