Magnetic properties of Fe2n and (FePt)n clusters and magnetic anisotropy of transition metal dimers

Effect of structure on the magnetic anisotropy ofL10FePt nanoparticles

“…This result is also in good agreement with the results of Ref. 44 Fe 2 turns out to exhibit very small anisotropy owing to the relatively small SOC of the Fe atom. The SOC of Fe atom is 81.6 meV and of the Pt atom is nearly 7 times greater 544 meV 45 .…”

“…The large magnetic moment of Fe in this dimer can be attributed to the charge transfer from the 3d orbital of Fe to the 5d orbital of the Pt atom, which creates a polarization and an extra "hole charge" on the Fe atom. 44 The MCA for FePt dimer is 10.37 meV (with the easy axis perpendicular to the dimer axis). This value is higher than the value for Fe 2 , because the values of both the spin and orbital momenta are larger in the FePt dimer.…”

“…In particular, it is known that the magnetic properties of nanoparticles depend on the size, shape and the way of synthesizing. 11 Gas-phase particles can in fact exhibit lower MCA than perfectly-ordered bulk L1 0 alloys, because (i) their internal structure may not be perfect L1 0 , and individual particles can become multiply-intertwined, (ii) the Pt atoms may tend to migrate towards the surface, 43,44 or (iii) an inhomogeneous alloying may be present from the beginning, as indicated by the EXAFS measurements by Antoniak. 55 The enhancement of surface-to-volume ratio (and hence the size) of a nanoparticle plays a significant role in its MCA.…”

Theoretical DFT study of homonuclear and binary transition-metal dimers

“…Among these, Pt-based [24][25][26][27] and Au-based [28][29][30] dimers have attracted research interest because of their fascinating properties in relation to their homonuclear counterparts. The presence of a second metallic component produces a synergistic effect that improves many of the relevant properties for technological applications, response associated to their electronic structure changes.…”

“…the proposed ground state is not conclusive for some of the heteronuclear dimers studied in this work. A number of other DFT schemes have been employed to study different heteronuclear dimers (or atomic clusters), for example, Pt-Au [25], Pt-Fe [26], Pd-Ag [31], Rh-Co [32], and more recently Pt-(Ti, V) [27], and Pd-Al [33] all of which reproduce some of the experimental data reasonably well depending on the approximation employed. This stimulates a systematic study in technologically relevant bimetallic systems, while gaining insight on relevant physical properties under different theoretical approaches such as DFT.…”