Orbital and spin magnetic moments of TPt3 (T=V, Cr, Mn, Fe, and Co)

Magnetic and crystallographic characterization of Pt(3)Mn(x)Cr(1-x) by XMCD and x-ray diffraction

We have performed XMCD and diffraction measurements on the Pt(3)Mn(x)Cr(1-x) alloy, which show that the magnetization of Pt is independently influenced by the Mn or Cr 3d orbital. We find that the magnetic moment on Pt, and its decomposition into spin and orbital components, is uniquely determined by the relative number of Mn and Cr neighbors. We then investigate the effect of pressure on the magnetization of Pt in the Pt(3)Mn(0.5)Cr(0.5) alloy. Our high pressure data enable us to conclude that at 14 GPa the spin and orbital polarization of the Pt 5d band are augmented by about 70%, with no interaction between them.

An ab initio study of the magnetic-metallic CoPt(3)-Au interfaces

The new challenging field of fabrication and interconnection of inorganic nanostructures is giving new impetus to the study of solid-solid interfacial properties. In nanocrystals made of two domains of different chemical composition and sharing an interface, the interfacial behavior is indeed critical for the stability of such an interface, and also in determining the mutual interactions of the two domains. Following a recent study by our group on the growth of colloidal nanocrystal heterodimers made of a domain of Au and a domain of CoPt(3), we report here an ab initio density functional theory study of the structural and electronic properties of Au/CoPt(3) interfaces. We have investigated the structure of different bulk CoPt(3) facets and of Au atoms adsorbed on CoPt(3). We calculated CoPt(3) and Au surface energies, Au/CoPt(3) interfacial energies as well as adsorption energies of Au atoms on CoPt(3) and Au, and we can draw some important conclusions about the growth mechanism of gold on the magnetic alloy. Furthermore, we give here a detailed description of surface and interfacial electronic properties, which in turn determine the possibility of tuning conductivity and magnetic properties in the nanostructure.