The Al 0 . 2 1 Mn 0 . 7 8 PS 3 , Al 0 . 1 5 Cd 0 . 8 3 PS 3 , In 0 . 2 0 Cd 0 . 7 0 PS 3 and Ga 0 . 2 8 Cd 0 . 5 8 PS 3 compounds have been synthesized by the cation-exchange process used for other cationic species of the same family. These compounds were characterized by X-ray diffraction , Fourier transform infrared spectroscopy, ICP plasma analyses, photoconductivity and electrochemical impedance spectroscopy. The compounds synthesized show electrical conductivities (σ) of the order of 10 - 9 to 10 - 1 0 Scm - 1 at 298K and photoconductive effect. The physical properties of the new Al 3 + materials reveal the same behavior as our previous report on In 3 + and Ga 3 + compounds.