Half-Metallic Ferromagnetism and Surface Functionalization-Induced Metal鈥揑nsulator Transition in Graphene-like Two-Dimensional Cr2C Crystals

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• 作者：Chen Si ; Jian Zhou ; Zhimei Sun
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：7
• 期：31
• 页码：17510-17515
• 全文大小：352K
• ISSN：1944-8252

文摘

Graphene-like two-dimensional materials have garnered tremendous interest as emerging device materials for nanoelectronics due to their remarkable properties. However, their applications in spintronics have been limited by the lack of intrinsic magnetism. Here, using hybrid density functional theory, we predict ferromagnetic behavior in a graphene-like two-dimensional Cr₂C crystal that belongs to the MXenes family. The ferromagnetism, arising from the itinerant Cr d electrons, introduces intrinsic half-metallicity in Cr₂C MXene, with the half-metallic gap as large as 2.85 eV. We also demonstrate a ferromagnetic鈥揳ntiferromagnetic transition accompanied by a metal to insulator transition in Cr₂C, caused by surface functionalization with F, OH, H, or Cl groups. Moreover, the energy gap of the antiferromagnetic insulating state is controllable by changing the type of functional groups. We further point out that the localization of Cr d electrons induced by the surface functionalization is responsible for the ferromagnetic鈥揳ntiferromagnetic and metal to insulator transitions. Our results highlight a new promising material with tunable magnetic and electronic properties toward nanoscale spintronics and electronics applications.