Defect states and kinetic parameter analysis of ZnAl2O4 nanocrystals by X-ray photoelectron spectroscopy and thermoluminescence

Megha Jain; Manju; Ravi Kumar; Sung Ok Won; Keun Hwa Chae; Ankush Vij; Anup Thakur

doi:10.1038/s41598-019-57227-8

Defect states and kinetic parameter analysis of ZnAl₂O₄ nanocrystals by X-ray photoelectron spectroscopy and thermoluminescence

Sci Rep. 2020 Jan 15;10(1):385. doi: 10.1038/s41598-019-57227-8.

Authors

Megha Jain^{1

2}, Manju^{1

2}, Ravi Kumar³, Sung Ok Won⁴, Keun Hwa Chae⁴, Ankush Vij⁵, Anup Thakur⁶

Affiliations

¹ Punjabi University, Advanced Materials Research Lab, Department of Basic and Applied Sciences, Patiala, 147 002, India.
² Punjabi University, Department of Physics, Patiala, 147 002, India.
³ National Institute of Technology, Center for Material Science & Engineering, Hamirpur, 177 005, India.
⁴ Korea Institute of Science and Technology, Advanced Analysis Center, Seoul, 02792, South Korea.
⁵ Amity University Haryana, Nanophosphors Lab, Department of Physics, Gurgaon, 122 413, India. vij_anx@yahoo.com.
⁶ Punjabi University, Advanced Materials Research Lab, Department of Basic and Applied Sciences, Patiala, 147 002, India. dranupthakur@gmail.com.

Abstract

Defect states in ZnAl₂O₄ have a significant role in its applicability as a luminescent material. To understand the nature and distribution of defects in its crystal lattice, thermoluminescence (TL) study has been carried out. Excellent TL response is observed from γ- and ultraviolet-irradiated samples at different doses and exposure durations, respectively. Different type of fuels employed in combustion synthesis show a remarkable effect on the trap distribution and hence luminescence properties. Shallow and deep traps are observed in crystals attributed to O^- vacancies and F⁺ centers. The mechanism of trapping, retrapping and recombination have been depicted through schematic band model diagram. X-ray photoelectron spectroscopy indicated the presence of various types of defects specifically Al_Zn antisite defect, oxygen and zinc vacancies which are further upheld by photoluminescence and Raman spectroscopy. All results when summed up, predict ZnAl₂O₄ to be a quality material for dosimetry.