First-principles study of a Mn-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>In</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Se</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> monolayer: Coexistence of ferromagnetism and ferroelectricity with robust half-metallicity and enhanced polarization
Chunmei Zhang, Lei Zhang, Cheng Tang, Stefano Sanvito, Bo Zhou, Zhenyi Jiang, Aijun Du
Abstract
Two-dimensional (2D) materials with coexistence of ferromagnetism (FM) and ferroelectricity (FE) are rare. By using first-principles modeling, here we report that doping of magnetic transition metal (TM) atoms in FE monolayer ${\mathrm{In}}_{2}{\mathrm{Se}}_{3}$ could introduce giant local FM magnetic moments ($4\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}$ per Mn atom). The exchange splitting energy, and the ${C}_{3\ensuremath{\nu}}$ crystal field together with the hybridization of the $\mathrm{Mn}\text{\ensuremath{-}}d$ and $\mathrm{Se}\text{\ensuremath{-}}p$ orbitals result in spin-polarized states near the Fermi surface. More interestingly, the asymmetric charge distribution of the Jahn-Teller ion ($\mathrm{M}{\mathrm{n}}^{3+}{d}^{4}$) further lift the twofold degeneracy of the Mn-d e${1}^{*}$ states. This affects the band structure and enhances the FE polarization in monolayer ${\mathrm{In}}_{2}{\mathrm{Se}}_{3}$. Our work paves the way for tailoring FM in 2D FE via doping magnetic moments from TM atoms. The half-metallicity combined with the enhanced FE polarization make Mn-doped ${\mathrm{In}}_{2}{\mathrm{Se}}_{3}$ a candidate for potential applications in information technology and spintronic devices.