Half metallic ferromagnetic and transport behavior of rare earth based CdGd2(S/Se)4 spinels

Spinel chalcogen compounds have garnered significant interest in recent ages because of their promising potential in optoelectronic and thermoelectric device applications. Here, we undertake an inclusive analysis of the structural, mechanical, electronic, magnetic, optical, and transport response of CdGd2(S/Se)4 utilizing WIEN2k code based on DFT. The determination of the crystal structure's ground state and the material's thermodynamic stability is investigated through energy vs. volume plots and ∆Hf calculation. Our analysis, including Poisson (v) and Pugh (B/G) ratios, reveals the ductile nature of the studied composition. Band gap assessments are conducted using the TB-mBJ approach, revealing the semiconducting nature of investigated compounds with direct band characteristics. Specifically, calculated band gap values are 2.2 for CdGd2S4 and 1.8 eV for CdGd2Se4. Additionally, analysis of optical properties and transport response underscores the perspective of these compositions for diverse optoelectronic and thermoelectric devices. [Display omitted] •Theoretical investigation of Gd-based chalcogenides CdGd2(S/Se)4 in ferromagnetism, and spintronic applications.•The ferromagnetism due to exchange mechanism of electrons rather than clustering.•Half metallic ferromagnetism confirm the complete spin polarization.•Direct band gap nature with bang gap values of 2.2 eV and 1.8 eV are estimated using mBJ potential.•Ultralow low thermal conductivity increases the impotance for thermoelectric device fabrication.