Interrelated emission and spin–spin relaxation feature mediated by V_O⁺ defects in Gd₂O₃ nanorods subjected to swift ion impact

Abstract

We report on the manifestation and interconnected photoluminescence and electron paramagnetic resonance responses in gadolinium oxide (Gd₂O₃) nanorods subjected to 80 MeV carbon ion irradiation. On increasing the irradiation fluence between 1 × 10¹¹ and 3 × 10¹² ions/cm², the emission associated with neutral oxygen vacancies (V_Ox), positioned at ~350 nm, undergoes a steady increase compared to that associated with singly charged vacancies (V_O⁺), located at ~414 nm. The enhancement of spin–spin relaxation time (τ_ss) is ascribed to a substantial changeover from V_O⁺ to V_Ox defects with irradiation, the former being recognized as the major contributor to paramagnetic centres. Interconnected luminescence and spin–spin relaxation could provide insight for making advanced nanophosphors and spin valve elements.

Keywords:

• Rare earth
• ion irradiation
• luminescence
• defects
• paramagnetic centre

Acknowledgements

The authors acknowledge the pelletron staff of IUAC, New Delhi for providing good quality ion beam facilities. Help and support from Dr. D.K. Avasthi and scientific staff during the irradiation experiments is acknowledged. We also acknowledge the scientific staff of the SAIF, IIT-M for providing the EPR facility.

Funding

This work was supported by the IUAC, New Delhi [grant number 50307/2011] and [grant number 56322/2014].