Theoretical study on the structure of ternary compounds AMn(2)X(2) (A = Ba, Ca and Y; X = Sn, Ge, and Si)

In advanced material several parameters as temperature, pressure, structure, composition and disorder determine their properties. Band structure calculations have been used to identify the electronic, structural, and magnetic properties of the layered ternary compound AMn(2)X(2) (A = Ba, Ca, Y and X = Sn, Ge, and Si). The calculations have been performed using the scalar-relativistic full potential linearized augmented plane wave method (FLAPW). The equilibrium lattice parameters, atomic positions in the unit cell, inter atomic distances, the band structure, density of states (DOS) and spin magnetic moment in the unit cell are presented. The DOS shows a typical conductive electronic structure for the system. Metal excess behavior was observed due to the high concentration of Mn-3d electrons just down Fermi level epsilon(f). The magnetic behavior introduces new aspect about the magnetic moments for such ternary structures. The magnetic moment of the studied compounds jumps to high value as the unit cell volume is increased above 180 angstrom(3) or the Mn-X bond length is greater than 2.5 angstrom. (C) 2013 Elsevier B. V. All rights reserved.