A comprehensive study on the electronic structure, dielectric and optical properties of alkali-earth metals and transition metal hydroxides M(OH) 2 .

In the present work, the physical properties of alkali-earth metal and transition metal hydroxides are comprehensively investigated using the density functional theory. Here, the alkali-earth metals Ca, Mg, and transition metals Cd, Zn are considered from the II-A and II-B groups in the periodic table of elements. The first principle electronic structure calculations show that these bulk hydroxide materials are direct band gap material. Ca(OH) 2 and Mg(OH) 2 exhibit an insulating behavior with a very large band gap. However, Cd(OH) 2 and Zn(OH) 2 are found to be wide band gap semiconductors. The dielectric and optical studies reveal that these materials have a high degree of anisotropy. Hence, the light propagation in these materials behaves differently in the direction perpendicular and parallel to the optical axis, and exhibits birefringence. Therefore, these materials may be useful for optical communication. The calculated electron energy loss suggests that these materials can also be used for unwanted signal noise suppression. The wide band gap makes them useful for high-power applications. Moreover, Ca(OH) 2 and Mg(OH) 2 are found to be suitable for dielectric medium.