A tight-binding calculation of the magnetic properties of TPt (T identical to 3d transition element) ordered alloys with CuAu structure

Abstract

A tight-binding type self-consistent band calculation is performed to study the magnetic properties of the ordered TPt (T identical to V, Cr, Mn, Fe, Co and Ni) alloys with CuAu structure within the Hartree-Fock approximation of the Hubbard model for their spin polarisation. Global features of their ground-state magnetic properties such as phase stability and local moments are explained successfully. The characteristic tetragonality of the lattice is argued from the calculated uniaxial pressures to be a consequence of the spin polarisation.

Size versus electronic factors in transition metal Laves phase stability

“…as the dB or NB increases. (Note that the small C15 domain for SITB = 60 (Mn) and 61 (Fe) is due to the presence of magnetism [23].) In addition, the upper cubic Laves domain gives way to a small Bcc-based C l l b domain as found experimentally.…”

Annealing environment effects on the microstructure and magnetic properties of FePt–TiO2 and CoPt–TiO2 nanocomposite films

“…The surface energy of an alloy is proportional to its bonding energy E b [28]. The CoPt has smaller E b and thus smaller driving force for the coalescence than those of FePt [29,30]. Therefore, the coalescence probability between the CoPt grains could be weaker than that between the FePt grains, despite the lower diffusion barriers between CoPt grains than that between FePt grains due to the oxide formation.…”

FePt and CoPt nanoparticles co-deposited on silicon dioxide—a comparative study

“…According to previous studies [18,19], the reduction of surface energy, which occurs during the coalescence process of two clusters, is energetically balanced by the increase of temperature of the coalesced nanoparticle to satisfy the energy conservation law. The local increase of temperature is proportional to the bond energy E b of the alloy [18]; therefore, since FePt exhibits a higher E b (∼6.33 eV) than CoPt (∼4.41 eV) [20], the same coalescence process of the two alloys would lead to higher local temperatures for the coalesced FePt nanoparticles, favoring their disorder/order structural transformation. All the samples exhibit a bimodal PSD (figure 2).…”