Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 5 (2018) 17641–17647 www.materialstoday.com/proceedings 2214-7853© 2018 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of Materials Processing and characterization. ICMPC_2018 Effect of Co/Ni co-doping in CeO2on structural, optical and vibrational properties Saurabh Tiwari a , Sajal Biring b , Somaditya Sen a * a Metallurgical Engineering and Material Sciences, Indian Institute of Technology Indore, India b Electronic Engg., Ming Chi University of Technology, New Taipei City, Taiwan Abstract Ce 1-x-y Co x Ni y O 2 (x=0.0125, y=0.0125) is synthesized by sol-gel method. The structural, optical and vibrational properties of synthesized nanoparticles have been analyzed by X-ray diffraction (XRD), UV-Vis spectroscopy and Raman spectroscopy. XRD and Raman spectroscopy are pointing out the generation of strain in lattice and reduction of crystallite size. Raman broad peak at ~600 cm -1 attributes to presence of oxygen vacancies in lattice. X-ray absorption near edge structure (XANES) is used for observing the oxidation state of Ce in prepared samples. © 2018 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of Materials Processing and characterization. Keywords: Sol-gel; Strain; Bandgap; Urbach energy 1. Introduction To improve the functionality of nanomaterials, doping process is a very important tool. In doping parent element is substituted by dopant which causes tuning of various properties of nanomaterials like structural, optical, electrical, and magnetic etc. Cerium oxide based nano materials has got greater interest in researchers. In recent time there are many applications found for multifunctionality and applicability like catalysis, biomedical, solid oxide fuel cells, gas * Corresponding author. E-mail address: phd1501181003@iiti.ac.in