Effects of Nanoparticle Geometry and Temperature on the Structural Evolution in FeCo Nanoalloys
Acta Physica Polonica. A
Eects of nanoparticle size (2.06.0 nm) and shape (spherical and cubic) on structural characteristic of atomic ordering processes and order-disorder transformation in B2-type ordered equiatomic-FeCo nanoalloys have been studied by combining electronic theory of alloys in the pseudopotential approximation with Ising-type Hamiltonian site exchange Monte Carlo simulation method. Structural evolutions in amorphous nanoparticles (26 nm) of Fe50Co50 alloy have been utilized via molecular dynamic
... cular dynamic simulations from room temperatures to 1700 K temperatures. It has been shown that disordering starts at surface and propagates into volume of nanoparticles with increasing temperature. FeCo nanoparticles with critical dimensions more than 5 nm have order-disorder transformation behavior almost similar with bulk B2FeCo alloys irrespective of their shape. Molecular dynamic analyses indicate that short-and medium-range ordered atomic structures exist in quenched Fe50Co50 nanoparticles at room temperature. Deformed bcc structures and deformed icosahedron structures are most probable atomic congurations for 2, 4, 6 nm particles of Fe50Co50 nanoalloy.