Study of nanostructure model systems (synthesis, characterization and manipulation) and heavy fermion systems.

• Grant number: 07/05871-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): January 01, 2008
• Effective date (End): December 31, 2009
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Carlos Rettori
• Grantee: José Marcelo Vargas
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 06/60440-0 - Study of strongly correlated systems in extreme conditions, AP.TEM

Abstract

In the present project two basic research lines are presented. The aim of the first one is related to the chemical synthesis of intermetallic nanoparticles A_{1-x}M_x, where A= Cu, Ag, Al, Pt, and M = Transition Metals 3d^n (M = Fe, Co, Mn) or Rare-Earths 4f^n (M = Gd, Nd, Er), varying the chemical composition and the mean particle size (2-15 nm). About the composition two extremes will be studied: in the diluted case, with x < 0.01 (inside the particle the magnetic specimens are isolated), and in the concentrated case, with x ~ 0.50 (with strong interactions between the magnetic specimens, intra and inter particles). About the mean size, we shall study the finite size effect on the structural, electronic and magnetic properties and the correlation between them. In connection to the nanoparticle manipulation, we will try to develop the technique to build up nanoparticle self-assembled systems (like thin-film), which are of great interest for the study of their collective properties.The second research line is related to the bulk systems. In particular, the aim of this proposal corresponds to the experimental and theoretical study of the crystalline-field-effect in the ground state of the Rare-Earths (Nd, Gd, Er), diluted in the monocrystalline heavy-fermion system YbRh_2Si_2, and the reference compound LuRh_2Si_2. The measurements will be carried out in crystals already prepared and/or to be prepared by our collaborators Profs. Saul B. Oseroff and Zachary Fisk. Moreover, in the present proposal, the fabrication and characterization of the new monocrystalline samples are also considered.