Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2017-06-01

Journal: NANO RESEARCH

Included Journals: Scopus、EI、SCIE

Volume: 10

Issue: 6

Page Number: 1972-1979

ISSN: 1998-0124

Key Words: spintronics; Dirac half metal; YN2 monolayer; ferromagnetism

Abstract: In spintronics, it is highly desirable to find new materials that can simultaneously possess complete spin-polarization, high-speed conduction electrons, large Curie temperature, and robust ferromagnetic ground states. Using first-principles calculations, we demonstrate that the stable YN2 monolayer with octahedral coordination is a novel p-state Dirac half metal (DHM), which not only has a fully spin-polarized Dirac state, but also the highest Fermi velocity (3.74 x 10(5) m/s) of the DHMs reported to date. In addition, its half-metallic gap of 1.53 eV is large enough to prevent the spin-flip transition. Because of the strong nonlocal p orbitals of N atoms (N-p) direct exchange interaction, the Curie temperature reaches over 332 K. Moreover, its ferromagnetic ground state can be well preserved under carrier doping or external strain. Therefore, the YN2 monolayer is a promising DHM for high-speed spintronic devices and would lead to new opportunities in designing other p-state DHMs.