TY - JOUR
T1 - Local structural studies through EXAFS and effect of Fe2+or Fe3+existence in ZnO Nanoparticles
AU - Rajan, Chithira Pulickalputhenpura
AU - Abharana, Nagendra
AU - Jha, Shambhu Nath
AU - Bhattacharyya, Dibyendu
AU - John, Teny Theresa
N1 - Funding Information:
We would like to thank Sophisticated Analytical Instrument Facility (SAIF) IIT-Madras for VSM and ESR facilities, Advanced Centre for Material Science (ACMS), IIT Kanpur for XPS, and IISER Bhopal for SQUID measurements. We also acknowledge the Central Sophisticated Instrumentation Facility (CSIF), BITS Pilani K K Birla Goa Campus, for the Raman measurement. C.P.R. thankfully acknowledge the Council of Scientific and Industrial Research (CSIR) for the Senior Research Fellowship (SRF) (09/919(0034)/2018- EMR-I). T.T.J. would like to thank the Science and Engineering Research Board (SERB, project no. ER/2016/ 005331) for financial support. The authors would like to acknowledge the Department of Science and Technology (DST), Govt. of India, for the financial support under the DST-FIST scheme (SR/FST/PS-I/2017/21).
Funding Information:
We would like to thank Sophisticated Analytical Instrument Facility (SAIF) IIT-Madras for VSM and ESR facilities, Advanced Centre for Material Science (ACMS), IIT Kanpur for XPS, and IISER Bhopal for SQUID measurements. We also acknowledge the Central Sophisticated Instrumentation Facility (CSIF), BITS Pilani K K Birla Goa Campus, for the Raman measurement. C.P.R. thankfully acknowledge the Council of Scientific and Industrial Research (CSIR) for the Senior Research Fellowship (SRF) (09/919(0034)/2018-EMR-I). T.T.J. would like to thank the Science and Engineering Research Board (SERB, project no. ER/2016/005331) for financial support. The authors would like to acknowledge the Department of Science and Technology (DST), Govt. of India, for the financial support under the DST-FIST scheme (SR/FST/PS-I/2017/21).
Publisher Copyright:
© 2021 American Chemical Society. All rights reserved.
PY - 2021/1/1
Y1 - 2021/1/1
N2 - A simple solution-based chemical precipitation method was used to synthesize the Fe-doped ZnO nanoparticles. X-ray Photoelectron Spectroscopy (XPS) measurement showed that mostly Fe2+ions are incorporated in a lower percentage of Fe doping, while a higher percentage leads to Fe3+. The broad absorption band in the visible range shows the d-d crystal field transitions between the multiplets of 3d5configuration of the high spin Fe3+substituting Zn2+under the influence of a tetrahedral ZnO crystal field. Raman measurement also supports the optical absorption data. ESR results show that the occurrence of broad signals is due to the exchange interactions among the TM ions in the doped samples. Fe exists in a mixed phase in Fe1 and the wide curve in Fe10 is due to the exchange interaction among Fe3+-Fe3+. EXAFS measurements confirm that the spectral features showing the peak edge position is similar to Fe2O3corresponding to the Fe3+state. From this, it can be inferred that Fe exists mostly in a +3 oxidation state in all the samples, but there may be existence of +2 states in the surface layers as observed from XPS measurement. Fe1 shows RTFM with a coercivity of ~70 Oe. The non-saturating, linear magnetic moment at higher applied magnetic field is due to the paramagnetic contribution from the uncoupled Fe3+ ions.
AB - A simple solution-based chemical precipitation method was used to synthesize the Fe-doped ZnO nanoparticles. X-ray Photoelectron Spectroscopy (XPS) measurement showed that mostly Fe2+ions are incorporated in a lower percentage of Fe doping, while a higher percentage leads to Fe3+. The broad absorption band in the visible range shows the d-d crystal field transitions between the multiplets of 3d5configuration of the high spin Fe3+substituting Zn2+under the influence of a tetrahedral ZnO crystal field. Raman measurement also supports the optical absorption data. ESR results show that the occurrence of broad signals is due to the exchange interactions among the TM ions in the doped samples. Fe exists in a mixed phase in Fe1 and the wide curve in Fe10 is due to the exchange interaction among Fe3+-Fe3+. EXAFS measurements confirm that the spectral features showing the peak edge position is similar to Fe2O3corresponding to the Fe3+state. From this, it can be inferred that Fe exists mostly in a +3 oxidation state in all the samples, but there may be existence of +2 states in the surface layers as observed from XPS measurement. Fe1 shows RTFM with a coercivity of ~70 Oe. The non-saturating, linear magnetic moment at higher applied magnetic field is due to the paramagnetic contribution from the uncoupled Fe3+ ions.
UR - http://www.scopus.com/inward/record.url?scp=85110040651&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.1c00881
DO - 10.1021/acs.jpcc.1c00881
M3 - Article
AN - SCOPUS:85110040651
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
ER -