Robust half-metallicity at the zincblende CrTe(0 0 1) surfaces and its interface with ZnTe(0 0 1)
Robust half-metallicity at the zincblende CrTe(0 0 1) surfaces and its interface with ZnTe(0 0 1)
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DOI：
10.1016/j.jmmm.2009.12.005
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发表时间：
2010-04
影响因子：
2.7
通讯作者：
F. Ahmadian;M. Abolhassani;S. J. Hashemifar;M. Elahi
中科院分区：
文献类型：
--
作者：
F. Ahmadian;M. Abolhassani;S. J. Hashemifar;M. Elahi
采用基于自旋密度泛函理论的全电子全势计算方法，研究了块体CrTe的立方闪锌矿(ZB)和六方NiAs结构、ZB CrTe的自由(001)面以及ZB CrTe与ZnTe(001)的界面。据报道，铁磁NiAs结构比铁磁ZB相稳定约0.26 eV，而ZB CrTe是半金属铁磁材料，半金属带隙约为2.90 eV。在从头算热力学框架下，研究了CrTe(001)表面的热力学稳定性。得到的相图表明，与铬端面相比，Te端面更稳定。我们讨论了CrTe(001)的Te和Cr理想终端都保持了块状的半金属性质，但与体值相比半金属带隙减小。计算了ZB-CrTe/ZnTe(001)界面的结构、电子、磁性和能带排列性质，在该异质结中观察到相当大的少数价带偏移，约为1.09 eV。
All electron full potential calculations based on spin density functional theory are performed to study cubic zincblende (ZB) and hexagonal NiAs structures of bulk CrTe, free (001) surfaces of ZB CrTe, and interface of ZB CrTe with ZnTe(001). The ferromagnetic NiAs structure is reported to be about 0.26eV more stable than the ferromagnetic ZB phase while ZB CrTe is found to be a half-metallic ferromagnet with a half-metallic gap of about 2.90eV. Thermodynamic stability of CrTe(001) surfaces are studied in the framework of ab-initio thermodynamic. The obtained phase diagram evidences more stability of the Te terminated surface compared with the Cr termination. We discuss that both Te and Cr ideal terminations of CrTe(001) retain bulk-like half-metallic property but with a reduced half-metallic gap compared with bulk value. The structural, electronic, magnetic, and band alignment properties of the ZB CrTe/ZnTe(001) interface are computed and a rather large minority valence band offset of about 1.09eV is observed in this heterojunction.