Electronic and Magnetic Structure of Transition-Metal Carbodiimides by Means of GGA+U Theory

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• 作者：Hongping Xiang ; Richard Dronskowski ; Bernhard Eck ; Andrei L. Tchougreff
• 刊名：Journal of Physical Chemistry A
• 出版年：2010
• 出版时间：November 25, 2010
• 年：2010
• 卷：114
• 期：46
• 页码：12345-12352
• 全文大小：313K
• 年卷期：v.114,no.46(November 25, 2010)
• ISSN：1520-5215

文摘

The electronic structures and magnetic properties of MNCN (M = Fe, Co, and Ni) have been investigated by density-functional theory including explicit electronic correlation through an ad hoc Coulomb potential (GGA+U). The results evidence CoNCN and NiNCN as type-II anti-ferromagnetic semiconductors (that is, intralayer ferromagnetic and interlayer anti-ferromagnetic), in accordance with experimental observations. Just like the prototype MnNCN, the MNCN phases, with M = Ni and Co, thus resemble the corresponding MO monoxides with respect to their magnetic and transport properties. By contrast, FeNCN remains (semi)metallic even upon applying a strong Coulomb correlation potential. This, most probably, is in contradiction with its observed optical transparency and expected insulating behavior and points toward a serious density-functional theory problem.