Spectroscopic Investigation of Defect Formation in Polycrystalline Ce0.8Zr0.2O2 Reveals Promising Radiation-Tolerant Properties

Strategic Insights -

Researchers at Jawaharlal Nehru University have conducted a comprehensive spectroscopic investigation of defect formation and structural stability in polycrystalline Ce0.8Zr0.2O2 subjected to 1.75 MeV Xe5+ ion irradiation. The study aimed to elucidate atomic-scale structural and electronic modifications using Raman spectroscopy, synchrotron-based x-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL). The research, funded by the Science and Engineering Research Board, University Grants Commission, and the Department of Science and Technology of the Government of India, revealed significant findings on the retention of crystallinity and accommodation of high defect densities in Ce0.8Zr0.2O2, making it a promising radiation-tolerant matrix for advanced nuclear and extreme-environment applications.

Key Takeaways:

  • Raman analysis revealed the emergence of Ce3+ and oxygen-vacancy-induced distortions, evident from peak broadening and shifts associated with B-1g, F-2g, and LO phonon modes.
  • XPS confirmed the partial reduction of Ce4+ to Ce3+ and Zr4+ to Zr3+, along with oxygen-vacancy formation that contributes to lattice relaxation and stabilization of the fluorite structure.
  • UV-Vis DRS measurements showed a decrease in optical bandgap from 3.37 to 2.71 eV and an increase in Urbach energy from 1.09 to 2.33 eV, indicating enhanced electronic disorder.
  • PL intensity was quenched upon irradiation due to increased non-radiative recombination through defect centers.
  • The study provides a coherent spectroscopic framework to understand irradiation-driven redox and defect processes in Ce0.8Zr0.2O2.

Statistics:

  • Damage region diameters of approximately 0.31 +/- 0.03 nm and 0.22 +/- 0.03 nm were quantified from Raman intensity ratios and FWHM broadening, respectively.
  • The optical bandgap decreased from 3.37 eV to 2.71 eV after irradiation.
  • The Urbach energy increased from 1.09 eV to 2.33 eV after irradiation.
  • The study was funded by the Science and Engineering Research Board (SERB) (Grant 10.13039/501100001843), the University Grants Commission, and the Department of Science and Technology of the Government of India.

Sources:

  • Spectroscopic Insights Into Structural and Electronic Modifications In Ce 0.8 zr 0.2 o 2 Under Low-energy Ion Irradiation. Journal of Applied Physics, 2025;138(13).
  • NewsRx. Investigators at Jawaharlal Nehru University Report Findings in Applied Physics (Spectroscopic Insights Into Structural and Electronic Modifications In Ce 0.8 zr 0.2 o 2 Under Low-energy Ion Irradiation). Journal of Physics Research. November 4, 2025; p 1212.