The increasing demand in the diverse device applications of transparent conducting oxides(TCOs) requires synthesis of new TCOs of n- or p-type conductivity.This article is about materials engineering of ZnO—SnO_2—ln_2O_3—Ga_2O_3 to synthesize powders of the quaternary compound Zn_(2-x)Sn_(1-x)Jn_xGa_xO_(4-δ) in the stoichiometry of x = 0.2,0.3,and 0.4 by solid state reaction at 1275℃.Lattice parameters were determined by X-ray diffraction(XRD) technique and solubility of ln~(3+) and Ga~(3+) in spinel Zn_2SnO_4 was found at 1275℃.The solubility limit of ln~(3+) and Ga~(3+) in Zn_2SnO_4 is found at below x = 0.4.The optical transmittance approximated by the UV—Vis reflectance spectra showed excellent characteristics while optical band gap was consistent across 3.2 eV with slight decrease along increasing x value.Carrier mobility of the species was considerably higher than the older versions of zinc stannate spinel co-substitutions whereas the carrier concentrations were moderate. The increasing demand in the diverse device applications of transparent conducting oxides (TCOs) requires synthesis of new TCOs of n- or p-type conductivity. This article is about materials engineering of ZnO-SnO_2-ln_2O_3-Ga_2O_3 to synthesize powders of the quaternary compound (2-x) Sn_ (1-x) Jn_xGa_xO_ (4-δ) in the stoichiometry of x = 0.2,0.3, and 0.4 by solid state reaction at 1275 ° C. The Lattice parameters were determined by X-ray diffraction The solubility limit of ln ~ (3+) and Ga ~ (3+) in Zn_2SnO_4 is found at below x = 0.4. The optical transmittance approximated by the UV-Vis reflectance spectra showed excellent characteristics while optical band gap was consistently across 3.2 eV with slight decrease along increasing x value. Carrier mobility of the species was considerably higher than the older versions of zinc stannate spinel co-substitutions but the carrier concentrations were mode rate.