Tuning magnetic properties of Cr2M2C3T2 (M = Ti and V) using extensile strain
Tuning magnetic properties of Cr2M2C3T2 (M = Ti and V) using extensile strain
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DOI：
10.1016/j.commatsci.2017.08.016
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发表时间：
2017-11
影响因子：
3.3
通讯作者：
Jianhui Yang;Xuepiao Luo;Xumeng Zhou;Shaozheng Zhang;Jia Liu;Y. Xie;L. Lv;Liang Chen
中科院分区：
文献类型：
--
作者：
Jianhui Yang;Xuepiao Luo;Xumeng Zhou;Shaozheng Zhang;Jia Liu;Y. Xie;L. Lv;Liang Chen
采用密度泛函理论研究了拉伸应变对Cr2 M2 C3 T2（M = Ti，V，Nb，Ta; T = OH，O，F）磁性能的影响.计算结果表明，在无应变状态下，Cr2 Ti 2C 3 O2和Cr2 V2 C3 O2的铁磁排列在能量上是有利的.居里温度分别为720.6 K和246.8 K，使用平均场近似海森堡模型计算。其他系统是反铁磁的，铬原子的磁矩（MCr）大于1.9 μB。对于从-5%到5%的延伸应变，反铁磁排列总是对Cr2 Nb 2C 3 T2和Cr2 Nb 2C 3 T2系统有利。而Cr2 Ti 2C 3 T2和Cr2 V2 C3 T2发生了铁磁-反铁磁（或反铁磁-铁磁）相变，而Cr2 Ti 2C 3 O2没有.对于所有Cr2 M2 C3 T2系统，Cr原子的磁矩随着拉伸应变从−5%增加到5%而单调增加。投影态密度表明Cr-3d轨道随着应变的增加而变得更加局域化，并且费米能级附近的态密度降低，这可能降低电导率。本研究表明，Cr2 M2 C3 T2（其中M = Ti，或V; T = O，OH，或F）的磁性和电子性能可以有效地调整使用拉伸应变。这促进了这些二维材料在自旋电子学和数据存储中的应用。
The influence of extensile strain on the magnetic properties of Cr2M2C3T2(M = Ti, V, Nb, and Ta; T = OH, O, and F) are investigated using density functional theory. Calculation results show that the ferromagnetic arrangement is energetically favorable for Cr2Ti2C3O2and Cr2V2C3O2in the strain-free state. The Curie temperatures are 720.6 K and 246.8 K, respectively, calculated using the Heisenberg model with mean-field approximation. Other systems are anti-ferromagnetic with magnetic moment of Cr atoms (MCr) larger than 1.9 μB. For extensile strains that vary from −5% to 5%, the anti-ferromagnetic arrangement is always energetically favorable for Cr2Nb2C3T2and Cr2Nb2C3T2systems. However, ferromagnetic to anti-ferromagnetic (or anti-ferromagnetic to ferromagnetic) phase transitions occurred for Cr2Ti2C3T2and Cr2V2C3T2, but not Cr2Ti2C3O2. The magnetic moment of Cr atoms increases monotonically as extensile strain increases from −5% to 5% for all Cr2M2C3T2systems. The projected density of states shows that Cr-3d orbitals become more localized as the strain increases, and that the density of states near the fermi level decreases, which may reduce the conductivity. This study indicates that the magnetic and electronic properties of Cr2M2C3T2(where M = Ti, or V; T = O, OH, or F) can be effectively tuned using extensile strain. This promotes the application of these two-dimensional materials in spin electronics and data storage.