AUTHOR=Li Yang 

TITLE=Hypothetical P63/mmc-Type CsCrCl3 Ferromagnet: Half-Metallic Property and Nodal Surface State

JOURNAL=Frontiers in Materials

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2020.00262

DOI=10.3389/fmats.2020.00262

ISSN=2296-8016

ABSTRACT=<p>This work focuses on the electronic, magnetic, and half-metallic behaviors and interesting surface state of a hypothetical CsCrCl<sub>3</sub> ferromagnet with a <italic>P6<sub>3</sub>/mmc</italic> space group, investigated using the spin-polarized generalized gradient approach (GGA) and spin-polarized GGA plus Hubbard <italic>U</italic> correction within the framework of density functional theory. The calculated total magnetic moment of <italic>P6<sub>3</sub>/mmc</italic> CsCrCl<sub>3</sub> is ∼7.397 μ<italic><sub><italic>B</italic></sub></italic>, and the main contribution to the total magnetism is from the Cr atoms. Based on the obtained spin-polarized band structures, we confirm that this hypothetical CsCrCl<sub>3</sub> ferromagnet is a half-metal with 100% spin-polarization. Without spin-orbit coupling, i.e., when the spin and orbit degrees of freedom are dependent, we found an interesting nodal surface state at the <italic>k<sub><italic>z</italic></sub></italic> = π plane due to the <italic>P6<sub>3</sub>/mmc</italic> type lattice structure having a twofold screw axis <italic>S<sub>2</sub><sub><italic>z</italic></sub></italic>. Our study provides strong evidence that a protected nodal surface state can be achieved in magnetic materials.</p>