First-principles investigation on the structural, electronic, vibrational and magnetic properties of the Co-substituted orthorhombic SrSnO₃

Half-metallic (HM) ferromagnets provide an excellent possibility to design spintronic applications, yet a limited number of ferromagnetic materials are available which provide half-metallicity only in one spin channel. Moreover, often theoretically explored HM gap disappears when the material is synthesized experimentally due to small lattice mismatch happens which further hinders the advancement of spin-based applications. In this study, we have systematically explored the structural, electronic, formation, vibrational and magnetic properties of the Co-substituted SrSn_(1−x)Co_xO₃wherex=0,0.25,0.5,0.75 (SSCO) alloys by employing first-principles methods with hybrid functionals. The Co-doping at the Sn-site induced the spontaneous magnetism into the non-magnetic orthorhombic SrSnO₃ (SSO) perovskite material. Our calculations show that there are two ferromagnetic semiconductor materials found at the Co doping concentration of x = 0.5 & 0.75 with the large values of energy bandgaps. Furthermore, HM ferromagnetic ground state appears for the Co-doping of SSO at x = 0.25 which is vibrationally stable at the Г-point and has an integral magnetic moment of 1μ_B. The orthorhombic SrSn_0.75Co_0.25O₃ alloy can be the prospective contender for the spintronic applications due to its thermodynamic and dynamic stability and large value of the HM gap (0.38 eV).