Effect of zirconium oxide local structure on soft x-ray optical properties near the oxygen K-edge region

• Published in: Journal of applied physics Vol. 128; no. 6
• Main Authors: Sinha, Mangalika, Gupta, Rajkumar, Kiranjot, Singh, Amol, Modi, Mohammed H.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 14.08.2020
• Subjects: Applied physics; Electronic structure; Geometrical optics; Optical properties; Photoelectrons; Reflectance; Soft x rays; Spectrum analysis; Thin films; X ray absorption; X ray optics; X ray photoelectron spectroscopy; Zirconium; Zirconium oxides
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0010859

Zirconium oxide thin film serves as one of the potential material candidates in extreme ultraviolet/soft x-ray optics applications. The suitability of its application can be justified by investigating its optical performance in the working energy range. In this study, we have investigated the soft x-ray optical properties of a zirconium oxide thin film near the O K-edge region using the energy-dependent soft x-ray reflectivity (SXR) technique. The SXR and absorption measurements are performed using the Indus-2 soft x-ray reflectivity beamline BL-03. The optical constants (δ and β) in the energy range of 500–560 eV covering O K-edge are extracted by applying Kramers–Kronig relations. Experimentally obtained δ and β profiles show a prominent eg and t2g feature in the vicinity of O K-edge with the crystal field splitting of 2.9 eV. All features observed in the δ and β spectra are correlated with their electronic structure and composition of the zirconium oxide thin film. Details of correlation between structural and optical properties as determined by x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, and SXR analyses are discussed.