The anisotropy in the optical constants of quartz crystals for soft X‐rays. Issue 2 (19th February 2021)

• Record Type: Journal Article
• Authors: Andrle, A.; Hönicke, P.; Vinson, J.; Quintanilha, R.; Saadeh, Q.; Heidenreich, S.; Scholze, F.; Soltwisch, V.
• Is Part Of: Journal of applied crystallography. Volume 54:Issue 2(2021)
• Page Start: 402
• Page End: 408
• Publication Date: 2021-02-19
• Subjects: optical constants -- quartz -- anisotropy -- soft X‐ray reflectometry; Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S1600576720016325
• Languages: English
• ISSNs: 0021-8898

Abstract

Abstract : The refractive index of a y ‐cut SiO2 crystal surface is reconstructed from polarization‐dependent soft X‐ray reflectometry measurements in the energy range from 45 to 620 eV. The reconstructed anisotropy in the optical constants is also confirmed by ab initio Bethe–Salpeter equation calculations of the O K edge. Abstract : The refractive index of a y ‐cut SiO2 crystal surface is reconstructed from orientation‐dependent soft X‐ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions, a significant deviation of the measured reflectance at the Si L 2, 3 and O K absorption edges is observed. The anisotropy in the optical constants reconstructed from these data is also confirmed by ab initio Bethe–Salpeter equation calculations for the O K edge. This new experimental data set expands the existing literature data for quartz crystal optical constants significantly, particularly in the near‐edge regions.