Bothina H. Manasreh, Ph.D.ABDULLAH HUSSAIN ABDULLAH HZZAZI2022-06-042022-01-152022-06-04109685https://drepo.sdl.edu.sa/handle/20.500.14154/64293Thermoelectric materials have potential properties for utilizing waste heat. The computations are used to estimate the electronic structure of CoRhYSi (Y = Cr, Mn) Quaternary Heusler alloys, as well as their elastic and magnetic characteristics. The full-potential linearized augmented plane wave is used in the calculations.The exchange-correlations are addressed using Perdew–Burke and Ernzerhof's generalized gradient approximation (GGA-PBE). With the exception of CoRhCrSi and CoRhMnSi, which are simple ferromagnets that are approximately half metallic in nature, electronic structure calculations demonstrate that these compounds have a gap in the minority states band and are obviously half-metallic ferromagnets. The magnetic moments of the CoRhCrSi and CoRhMnSi compounds match relatively well with the Slater-Pauling rule, indicating half metallicity and high spin polarization for these compounds. The semi-classical Boltzmann theory was used to compute the Seebeck coefficient (S), electrical conductivity, and electronic thermal conductivity (𝑘𝑒) of CoRhYSi (Y = Cr, Mn) alloys, whereas Slack's equation was used to get the lattice thermal conductivity (𝑘𝐿).60enThesis