Research Information System
Journal of Physics and Chemistry of Solids, vol.215, 2026 (SCI-Expanded, Scopus)
AbstractAltermagnetism is a newly identified magnetic state having an antiferromagnetic order and spin split band structure, driven by symmetry and momentum. This allows for new multifunctional properties in 2D materials. Herein, we study the Janus monolayer of Cr2SeTeO. The monolayer settles into a fully compensated antiferromagnetic ground state having Néel temperature of 470 K. The Janus monolayer possess a semiconducting feature with an indirect band gap of 0.58 eV. Even without net magnetization, the electronic structure shows a large altermagnetic spin splitting of 828 meV. Uniaxial strain breaks the in-plane symmetry between the X and Y valleys causing a large, reversible valley polarization. The maximum valley polarization is found to be 166 meV in the valence band and 134 meV in the conduction band at ±4% strain. Combining uniaxial strain with hole doping activates intrinsic piezomagnetism, creating a finite switchable magnetic moment. The magnetic moment is −0.0272 μB per formula unit under −4% compressive strain and +0.0175 μB per formula unit under +4% tensile strain. The piezoelectric response was also measured and the obtained piezoelectric stress coefficient (e31) is 0.41 × 10−10 p.m./V while, the strain coefficient (d31) is 1.43 p.m./V. Thermoelectric transport calculations show large Seebeck coefficients and reduced lattice thermal conductivity which leads to better thermoelectric performance. The maximum figure of merit ZT is about 0.99 at 500 K under n-type doping. The results show Cr2SeTeO is a stable 2D altermagnetic material having good spin splitting, piezo-valley, piezomagnetic, piezoelectric, and thermoelectric responses. These performances suggest that it can be used in advanced multifunctional and spin-caloritronic devices.