Electronic and mechanical properties of rare earth monochalcogenides

In this paper, we have investigated the electronic and mechanical properties of rare earth (divalent, R+2X and trivalent, R+3X) monochalcogenides in rock-salt structured using the plasma oscillations theory of solids. We have presented the expressions relating the heteropolar gap (Ec), average energy gap (Eg), crystal ionicity (fi), electronic polarizability (αe) and bulk modulus (B) for rare earth chalcogenides with the plasmon energy (ħωp). The electronic and mechanical properties such as crystal ionicity, electronic polarizability and bulk-modulus of these compounds exhibit a linear relationship when plotted on a log–log scale against the plasmon energy (ħωp). A fairly good agreement has been found between the observed and calculated values of Ec, Eg, fi, αe and B for rare earth monochalcogenides.