Stability of ferromagnetism in diluted magnetic <i>Sr</i> _1−<i>x</i> <i>Cr</i> _<i>x</i> <i>X</i> (X = S, Se and Te) semiconductor doped by Cr under Hubbard correction and strain effect

Abstract This study focuses on the electronic, magnetic, and elastic features of strontium chalcogenides SrX ( X = S , Se , Te ) doped with chromium ( Cr ) using ab-initio calculations, in the presence and absence of the Hubbard correction (U) and strain effect. The results show that adding Cr induces a half-metallic behavior and a stable ferromagnetic phase, with spin polarisation reaching 100% in the absolute majority of cases. The stability of this phase is confirmed by negative formation energies and high Curie temperatures, above room temperature, achieving its maximum values of 464K, 475 K, and 570 K for SrS, SrSe, and SrTe, respectively, at 24% of the chromium portion. The effect of applied strains (2% and 4%) reveals a modulation of the electronic properties, visualized by the shift in density of state (DOS) and the decrease of the band gap. A strengthening of the magnetic interactions while retaining the half-metallic character is also observed under strain. Since Cr-doped SrS has large elastic moduli and remarkable mechanical properties, it is a perfect choice for strong spintronic devices and spin filters that need mechanical stability. Its ability to blend mechanical strength and ductility makes Cr-doped SrSe a promising material for magnetic tunnel junctions (MTJs) in MRAM. For flexible spintronic devices, including SpinFETs, Cr-doped SrTe is an excellent choice due to its enhanced ductility (increased B / G ratio) and maximal deformability. These results highlight the potential of Cr-doped SrX compounds to improve device performance, efficiency, and functionality by relying on the interaction of ferromagnetism and elastic property tuning. The combination of all our findings makes our compound promising for spintronic applications.