Multipiezo effect in altermagnet V2SeO monolayer at high temperature
Abid Zaman, Kakul Husain, Salhah Hamed Alrefaee, Hifsa Shahid, Muawya Elhadi, Anvar Nurmuhammedov, Rawaa M. Mohammed, Vineet Tirth, Ali Algahtani, Noureddine Elboughdiri
Abstract
Altermagnetism, characterized by a compensated magnetic order with momentum-dependent spin splitting, has recently gained attention as a potential platform for advanced spintronic technologies. When combined with multifunctional responses such as piezoelectricity, piezovalley, and piezomagnetism, exciting possibilities for strain-controlled magneto-electronic applications are opened. In this study, we investigated the Janus monolayer V 2 SeO, a two-dimensional altermagnetic material, using first-principles calculations. A high Néel temperature of 950 K confirmed the antiferromagnetic nature of the ground state. The material is thermodynamically and dynamically stable. Furthermore, V 2 SeO exhibits a direct band gap of 0.34 eV and non-relativistic spin-splitting (∼0.26 eV) at high-symmetry points, confirming its altermagnetic character. The broken mirror symmetry of the Janus structure enabled an out-of-plane piezoelectric effect, with calculated coefficients of e 31 = 49.90 pC/m and d31 = 0.25 pm/V. A strain-induced piezovalley effect yields a large valley polarization of up to 131 meV, while doping under strain induces a finite piezomagnetic response. These coexisting properties, including altermagnetism, piezoelectricity, piezovalley, and piezomagnetism, position monolayer V 2 SeO as a strong candidate for future strain-tunable spintronic and valleytronic devices applications. Its potential synthesis via exfoliation or chemical vapor deposition makes it experimentally accessible.