Multifunctional nanostructured Co-doped ZnO: Co spatial distribution and correlated magnetic properties

Author(s):Show less -

da Silva, Rafael T. ^[1] ; Mesquita, Alexandre ^[2] ; de Zevallos, Angela O. ^{[1, 3]} ; Chiaramonte, Thalita ^[4] ; Gratens, Xavier ^[5] ; Chitta, Valmir A. ^[5] ; Morbec, Juliana M. ^{[1, 6]} ; Rahman, Gul ^[7] ; Garcia-Suarez, Victor M. ^{[8, 9]} ; Doriguetto, Antonio C. ^[3] ; Bernardi, Maria I. B. ^[10] ; de Carvalho, Hugo B. ^[1]

Affiliation

^[1] Univ Fed Alfenas UNIFAL MG, Inst Ciencias Exatas, BR-37133840 Alfenas, MG - Brazil

^[2] Univ Estadual Paulista UNESP, Inst Geociencias & Ciencias Exatas, Dept Fis, BR-13500900 Rio Claro, SP - Brazil

^[3] Univ Fed Alfenas UNIFAL MG, Inst Quim, BR-37133840 Alfenas, MG - Brazil

^[4] Univ Fed Sao Joao Del Rei UFSJ, Dept Ciencias Nat, BR-36301160 Sao Joao Del Rei, MG - Brazil

^[5] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo, SP - Brazil

^[6] Univ Duisburg Essen, Fac Phys, D-47057 Duisburg - Germany

^[7] Quaid I Azam Univ, Dept Phys, Islamabad 45320 - Pakistan

^[8] Univ Oviedo, Dept Fis, Oviedo 33007 - Spain

^[9] Nanomat & Nanotechnol Res Ctr CINN, Llanera - Spain

^[10] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 20, n. 30, p. 20257-20269, AUG 14 2018.
• Web of Science Citations: 4

Abstract

In this report we present a systematic structural and magnetic analysis of Co-doped ZnO nanoparticles prepared via a microwave-assisted hydrothermal route. The structural data confirm the incorporation of Co ions into the wurtzite ZnO lattice and a Co concentration mainly near/at the surface of the nanoparticles. This Co spatial distribution is set to passivate the surface of the ZnO nanoparticles, inhibiting the nanoparticle growth and suppressing the observation of a ferromagnetic phase. Based on experimental and theoretical results we propose a kinetic-thermodynamic model for the processes of nucleation and growth of the Co-doped ZnO nanoparticles, and attribute the observed ferromagnetic order to a ferromagnetism associated with specific defects and adsorbed elements at the surface of the nanoparticle. Our findings give valuable contribution to the understanding of both the doping process at the nanoscale and the nature of the magnetic properties of the Co-doped ZnO system. (AU)

• FAPESP's process: 13/07909-4 - Preparation and characterization of magnetic oxides films nanostructured
• Grantee: Maria Inês Basso Bernardi
• Support type: Regular Research Grants
• FAPESP's process: 15/16191-5 - The research in new materials involving high magnetic fields and low temperatures
• Grantee: Gennady Gusev
• Support type: Research Projects - Thematic Grants