THE CHARACTERISTICS OF RARE-EARTH CHALCOGENIDES AND OXIDES

The electronic, optical, electrical and transport properties of rare e arth (Th, U, Pu, Sm) chalcogenides & oxides have been discussed. The v arious physical parameters such as ionicity, polarizability, bulk modu lus, cohesive energy, have been computed and compared with the reporte d data with special reference to monopole i.e. isomer shift. A discuss ion based on PVV theory has been presented for the derived homopolar g ap (E(h)), ionic gap (E(c)), Penn gap (E(p)), average gap (E(g)) corre lating ionicity with E(c) & E(g) as well as with various hyperfine int eractions.