Synthesis and atomic scale characterization of Er2O3 nanoparticles: enhancement of magnetic properties and changes in the local structure

Autor(es)

Correa, Eduardo L. ^[1] ; Bosch-Santos, Brianna ^[1] ; Freitas, Rafael S. ^[2] ; Potiens, Maria da Penha A. ^[1] ; Saiki, Mitiko ^[1] ; Carbonari, Artur W. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Pesquisas Energet & Nucl, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Fis, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Nanotechnology; v. 29, n. 20 MAY 18 2018.
• Citações Web of Science: 1

Resumo

In the investigation reported in this paper a modified thermal decomposition method was developed to produce very small Er2O3 nanoparticles (NPs). Particles structure, shape and size were characterized by x-ray diffraction and transmission electron microscopy which showed that the synthesis by thermal decomposition under O-2 atmosphere produced very small and monodisperse NPs, allowing the investigation of finite-size and surface effects. Results of magnetization measurements showed that the smallest particles present the highest values of susceptibility that decrease as particle size increases. Specific heat measurements indicate that the sample with the smallest NPs (diameter similar to 5 nm) has a Neel temperature of 0.54 K. The local structure of particles was investigated by measurements of hyperfine interactions with perturbed angular correlation spectroscopy using Cd-111 as probe nuclei replacing the cationic sites. Results showed that the relative population of sites 8b increases in both the core and surface layer of particles. (AU)

• Processo FAPESP: 14/14001-1 - Projeto e construção de um espectrômetro digital: um equipamento mais eficiente e moderno para investigação de materiais utilizando técnica PAC
• Beneficiário: Rajendra Narain Saxena
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/16191-5 - Pesquisas em novos materiais envolvendo campos magnéticos intensos e baixas temperaturas
• Beneficiário: Gennady Gusev
• Linha de fomento: Auxílio à Pesquisa - Temático