Title
Doping effects on the structural, magnetic, and hyperfine properties of Gd-doped SnO<inf>2</inf> nanoparticles
Date Issued
01 December 2014
Access level
metadata only access
Resource Type
journal article
Author(s)
Coelho-Júnior H.
Hidalgo P.
Cohen R.
Nagamine L.C.C.M.
da Silva S.W.
Brito H.F.
Universidade de Brasília
Universidade de Brasília
Universidade de Brasília
Publisher(s)
Kluwer Academic Publishers
Abstract
In this work we present the study of the structural, magnetic, and hyperfine properties of Gd-doped SnO2 nanoparticles synthesized by a polymer precursor method. The X-ray diffraction data analysis shows the formation of the rutile-type structure in all samples with Gd content from 1.0 to 10.0 mol%. The mean crystallite size is ~11 nm for the 1.0 mol% Gd-doped samples and it shows a decreasing tendency as the Gd content is increased. The analysis of magnetic measurements indicates the coexistence of ferromagnetic and paramagnetic phases for the 1.0 mol% Gd-doped sample; however, above that content, only a paramagnetic phase is observed. The ferromagnetic phase observed in the 1.0 mol% Gd-doped sample has been assigned to the presence of bound magnetic polarons which overlap to create a spin-split impurity band. Room-temperature 119Sn Mössbauer measurements reveal the occurrence of strong electric quadrupole interactions. It has been determined that the absence of magnetic interactions even for 1.0 mol% Gd-doped sample has been related to the weak magnetic field associated to the exchange interaction between magnetic ions and the donor impurity band. The broad distribution of electric quadrupole interactions are attributed to the several non-equivalent surroundings of Sn4+ ions provoked by the entrance of Gd3+ ions and to the likely presence of Sn2+ ions. The isomer shift seems to be nearly independent of the Gd content for samples with Gd content below 7.5 mol%.
Volume
16
Issue
12
Language
English
OCDE Knowledge area
Física de partículas, Campos de la Física
Scopus EID
2-s2.0-84919754157
Source
Journal of Nanoparticle Research
ISSN of the container
13880764
Sponsor(s)
Acknowledgments This work was financially supported by the Brazilian agencies CNPq, CAPES, FAP/DF, and FAPESP (proc. 2011/50556-0) Authors want to thank Dr. E. Guimarães for her help with the XRD experiments.
Sources of information: Directorio de Producción Científica Scopus