Title
Optical, structural and magnetic characterization of Bi2−xCrxTe3 nanocrystals in oxide glass
Date Issued
01 February 2020
Access level
metadata only access
Resource Type
journal article
Author(s)
Araujo C.M.
Mikhail H.D.
Guimarães E.V.
Rastrello L.R.
Silva A.C.A.
Dantas N.O.
Silva R.S.
Universidad Federal de Sao Paulo
Publisher(s)
Elsevier Ltd
Abstract
Chromium-doped bismuth telluride (Bi2−xCrxTe3) diluted magnetic semiconductor nanocrystals were successfully synthesized in a glass matrix by the fusion method with nominal Cr concentrations of x = 0.00, 0.05, and 0.10. Transmission electron microscopy confirmed the growth of nanocrystals with an average diameter of ~5.0 nm. Shifts in X-ray diffraction peaks with increasing x indicated substitutional inclusion of Cr ions (occupying Bi sites - CrBi) in the Bi2Te3 structure. The absorption spectra for x = 0.05 and 0.10 show two intense spin-allowed bands at ~425 and 635 nm and two minor spin-forbidden bands at ~650 and 685 nm. These bands were attributed to the Cr3+ d-d transitions, according to the crystal field theory. Finally, electron paramagnetic resonance spectra from the Bi2−xCrxTe3 nanocrystals displayed Cr3+ characteristics with spin 3/2 in the d3 state, thereby confirming the trivalent state of Cr ions in the Bi2Te3 structure.
Volume
241
Language
English
OCDE Knowledge area
Mineralogía
Electroquímica
Óptica
Subjects
Scopus EID
2-s2.0-85074228734
Source
Materials Chemistry and Physics
ISSN of the container
02540584
Sponsor(s)
The authors gratefully acknowledge financial support from the Brazilian agencies: MCT/CNPq , Capes , Fapemig , and Rede Mineira de Química (RQ-MG) supported by FAPEMIG (project CEX-RED-00010-4 ). We are also thankful for use of the facilities for the TEM measurements at the Laboratório Multiusuário de Microscopia de Alta Resolução (LabMic), Universidade Federal de Goiás.
Sources of information:
Directorio de Producción Científica
Scopus