Structural, optical and magnetic properties of Cr doped ZnO microrods prepared by spray pyrolysis method


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YILMAZ Ş., PARLAK M., ÖZCAN Ş., Altunbas M., McGlynn E., BACAKSIZ E.

APPLIED SURFACE SCIENCE, vol.257, no.22, pp.9293-9298, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 257 Issue: 22
  • Publication Date: 2011
  • Doi Number: 10.1016/j.apsusc.2011.05.017
  • Journal Name: APPLIED SURFACE SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.9293-9298
  • Keywords: Cr:ZnO, Micro rod, XPS, Photoluminescence, Ferromagnetism, ROOM-TEMPERATURE FERROMAGNETISM, THIN-FILMS, SEMICONDUCTORS, FABRICATION, SPECTRA
  • Middle East Technical University Affiliated: Yes

Abstract

A series of Cr-doped ZnO micro-rod arrays were fabricated by a spray pyrolysis method. X-ray diffraction patterns of the samples showed that the undoped and Cr-doped ZnO microrods exhibit hexagonal crystal structure. Surface morphology analysis of the samples has revealed that pure ZnO sample has a hexagonal microrod morphology. From X-ray photoelectron spectroscopy studies, the Cr 2p3/2 binding energy is found to be 577.3 eV indicating that the electron binding energy of the Cr in ZnO is almost the same as the binding energy of Cr3+ states in Cr2O3. The optical band gap E-g decreases slightly from 3.26 to 3.15 eV with the increase of actual Cr molar fraction from x = 0.00 to 0.046 in ZnO. Photoluminescence studies at 10 K show that the incorporation of chromium leads to a relative increase of deep level band intensity. It was also observed that Cr doped samples clearly showed ferromagnetic behavior; however, 2.5 at.% Cr doped ZnO showed remnant magnetization higher than that of 1.1 at.% and 4.6 at.% Cr doped samples, while 4.6 at.% Cr doped ZnO samples had a coercive field higher than the other dopings. (C) 2011 Elsevier B.V. All rights reserved.