Anomalous Hall and multipiezo phenomena in a two-dimensional altermagnetic Janus Cr<sub>2</sub>S<sub>2</sub>Se

Zaman A., Alrefaee S. H., Shahid H., Sottarov A., Asadullayeva S., Alreshidi R., ...More

RSC ADVANCES, vol.15, no.51, pp.43844-43852, 2025 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 15 Issue: 51
  • Publication Date: 2025
  • Doi Number: 10.1039/d5ra07306e
  • Journal Name: RSC ADVANCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, Directory of Open Access Journals
  • Page Numbers: pp.43844-43852
  • Open Archive Collection: Digital Heritage Collection
  • Azerbaijan State University of Economics (UNEC) Affiliated: No

Abstract

The emergence of altermagnetism, which combines a compensated magnetic configuration with momentum-dependent spin band splitting, has introduced new opportunities for spintronic research. In particular, the integration of altermagnetism with multifunctional properties such as piezoelectricity, piezovalley coupling, and piezomagnetism that offers a promising route toward strain-engineered magneto-electronic devices. Motivated by this perspective, we explored the two-dimensional Janus monolayer Cr2S2Se using density functional theory. Our results reveal that the system is both thermodynamically and dynamically stable, while its magnetic ground state is antiferromagnetic with a N & eacute;el temperature of approximately 320 K. The electronic structure demonstrates an indirect band gap of about 0.14 eV and pronounced non-relativistic spin splitting (similar to 0.46 eV) at the high-symmetry points, a clear hallmark of altermagnetic behavior. The lack of mirror symmetry in the Janus configuration further induces an out-of-plane piezoelectric response, yielding sizable piezoelectric coefficients (e31 approximate to 69.80 pC m-1 and d31 approximate to 0.36 pm V-1). Additionally, we observed a strain-driven piezovalley effect, producing a valley polarization as large as 142 meV. Interestingly, carrier doping under applied strain activates a finite piezomagnetic response. The coexistence of these distinct functionalities such as altermagnetism, piezovalley, piezoelectricity, and piezomagnetism that's positions Cr2S2Se as a compelling candidate for strain-tunable valleytronic and spintronic applications. Importantly, its potential fabrication via methods such as mechanical exfoliation or chemical vapor deposition enhances the experimental feasibility of this material.