Work

Magnetic semiconductors from functionalized Cr 2 C MXenes

Year: 2025

Type: article

Abstract: We report an ab initio investigation of functionalized and $3d$-electron-doped ${\mathrm{Cr}}_{2}\mathrm{C}$ MXenes. Upon functionalization, the ${\mathrm{Cr}}_{2}\mathrm{C}$ becomes chemically, dynamically, and mechanically stable, and it exhibits magnetic semiconducting behavior. ${\mathrm{Cr}}_{2}{\mathrm{CF}}_{2}$ stands out as a wide band gap semiconductor, possessing superexchange interaction mediated by F atoms within the layer; however, the applied strain transforms it from an indirect to a direct band gap semiconductor. Strong spin-phonon coupling found in ${\mathrm{Cr}}_{2}{\mathrm{CH}}_{2}$ is supported by the distorted Cr spin density due to the hydrogen environment. Two magnon branches, associated with two sublattice spins, are found in the ferromagnetic ${\mathrm{Cr}}_{2}{\mathrm{CO}}_{2}$ and antiferromagnetic ${\mathrm{Cr}}_{2}{\mathrm{CF}}_{2}$. Depending on the types of $3d$-electron dopants and functionalization, ${\mathrm{Cr}}_{2}\mathrm{C}$ MXenes (except for ${\mathrm{Cr}}_{2}{\mathrm{CO}}_{2}$) change from an indirect band gap magnetic semiconductor to different states of electronic and magnetic matter, including an exotic direct band gap magnetic bipolar semiconductor. In addition, we reveal a band inversion between the two highest valence bands in the Fe-doped ${\mathrm{Cr}}_{2}{\mathrm{CCl}}_{2}$.

Source: Physical review. B./Physical review. B

DOI: 10.1103/9k4g-kjgf

Authors: Yogendra Limbu, Hari Paudyal, Eudes Gomes da Silva, Denis R. Candido, Michael E. Flatté, Durga Paudyal

Institutions: University of Iowa, Eindhoven University of Technology

Language: English

Topic: MXene and MAX Phase Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green