TY - JOUR
T1 - Band gap reduction and redshift of lattice vibrational spectra in Nb and Fe co-doped PLZT
AU - Samanta, Shibnath
AU - Muralidhar, Miryala
AU - Sankaranarayanan, V.
AU - Sethupathi, K.
AU - Ramachandra Rao, M. S.
AU - Murakami, Masato
N1 - Funding Information:
This work has been supported by Japan Student Services Organization (JASSO), Shibaura Institute of Technology (SIT) under the Top Global University Project, Designed by Ministry of Education, Culture, Sports, Science and Technology in Japan and IIT Madras, India. The authors would like to acknowledge the support extended by Mr. Subhajit Nandy and Dr. Sudakar Chandran (Department of Physics, IIT Madras) in carrying out DRS measurements.
Publisher Copyright:
© 2017, Springer Science+Business Media, LLC.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - Nb and Fe co-doped PLZT (Pb0.97La0.02(Zr0.52Ti0.48)1−2x(Nb0.5Fe0.5)2xO3 for x = 0.00, 0.02, 0.04, 0.06 and 0.08) samples have been prepared using sol–gel method. X-ray diffraction (XRD) and Raman spectroscopy studies confirmed that the samples are single phase even for the highest tested doping of 8 mol% of Nb and Fe. Incorporation of Nb and Fe atoms into PLZT lattice has been confirmed by XRD study where a systematic peak shift has been observed with increasing dopant concentration. The lattice parameters are found to decrease gradually with increase in Nb and Fe contents. From Raman spectroscopic investigation, redshift of several modes has been observed. Rietveld refinement has been performed to correlate XRD results with the fitting of Raman spectra. A total of 14 distinguished modes have been identified by de-convolution of Raman spectra, and they are in good agreement with the theoretically calculated modes for PbTiO3 and also with those reported on PZT and PLZT previously. The Burstein–Moss shift of absorption edge has been observed by diffuse reflectance spectroscopy experiment, and the analysis shows change in band gap from 3.21 eV (for x = 0.00) to 2.59 eV (for x = 0.08). The underlying mechanisms and the observed electronic behavior have been confirmed and analyzed by photoluminescence study which revealed several transitions and supported the effect of Nb and Fe co-doping as observed from XRD and Raman spectroscopy.
AB - Nb and Fe co-doped PLZT (Pb0.97La0.02(Zr0.52Ti0.48)1−2x(Nb0.5Fe0.5)2xO3 for x = 0.00, 0.02, 0.04, 0.06 and 0.08) samples have been prepared using sol–gel method. X-ray diffraction (XRD) and Raman spectroscopy studies confirmed that the samples are single phase even for the highest tested doping of 8 mol% of Nb and Fe. Incorporation of Nb and Fe atoms into PLZT lattice has been confirmed by XRD study where a systematic peak shift has been observed with increasing dopant concentration. The lattice parameters are found to decrease gradually with increase in Nb and Fe contents. From Raman spectroscopic investigation, redshift of several modes has been observed. Rietveld refinement has been performed to correlate XRD results with the fitting of Raman spectra. A total of 14 distinguished modes have been identified by de-convolution of Raman spectra, and they are in good agreement with the theoretically calculated modes for PbTiO3 and also with those reported on PZT and PLZT previously. The Burstein–Moss shift of absorption edge has been observed by diffuse reflectance spectroscopy experiment, and the analysis shows change in band gap from 3.21 eV (for x = 0.00) to 2.59 eV (for x = 0.08). The underlying mechanisms and the observed electronic behavior have been confirmed and analyzed by photoluminescence study which revealed several transitions and supported the effect of Nb and Fe co-doping as observed from XRD and Raman spectroscopy.
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U2 - 10.1007/s10853-017-1425-7
DO - 10.1007/s10853-017-1425-7
M3 - Article
AN - SCOPUS:85026511666
SN - 0022-2461
VL - 52
SP - 13012
EP - 13022
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 22
ER -