THE CHARACTERISTICS OF RARE-EARTH CHALCOGENIDES AND OXIDES

The electronic, optical, electrical and transport properties of rare earth (Th, U, Pu, Sm) chalcogenides & oxides have been discussed. The various physical parameters such as ionicity, polarizability, bulk modulus, cohesive energy, have been computed and compared with the reported data with special reference to monopole i.e. isomer shift. A discussion based on PVV theory has been presented for the derived homopolar gap (E(h)), ionic gap (E(c)), Penn gap (E(p)), average gap (E(g)) correlating ionicity with E(c) & E(g) as well as with various hyperfine interactions.