Determination of the optical band gap and electronic transition type of powdered Ca2Fe2O5 brownmillerite

IF 3.8 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Optical Materials Pub Date : 2025-03-14 DOI:10.1016/j.optmat.2025.116947

S. F. Armendáriz, P. Amézaga-Madrid, S. F. Olive-Méndez, F. Espinosa-Magaña, D. Lardizábal-Gutiérrez

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引用次数: 0

Abstract

In this study, powdered Ca₂Fe₂O₅ was synthesized via a sol-gel method and characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and ultraviolet–visible–near infrared diffuse reflectance spectroscopy (UV–Vis–NIR DRS). The morphology of the particles was analyzed with SEM, the elemental composition was studied with EDX and XRD; the latter, along with ATR-FTIR, confirmed both the crystal phase and sample purity. The novelty of this study lies in the application of two recently developed methods for analyzing UV–Vis/NIR data, which allow the determination of the Tauc exponent when calculating the optical band gap from Tauc plots. Both methods indicated an indirect electronic transition in Ca₂Fe₂O₅, with the resulting optical band gap value being 1.62 eV. This indirect transition aligns with the results from theoretical works on the electronic band structure of the material. However, the obtained band gap is substantially lower than those reported in previous theoretical and experimental reports.

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来源期刊

Optical Materials 工程技术-材料科学：综合

CiteScore

6.60

自引率

12.80%

发文量

1265

审稿时长

38 days

期刊介绍： Optical Materials has an open access mirror journal Optical Materials: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review. The purpose of Optical Materials is to provide a means of communication and technology transfer between researchers who are interested in materials for potential device applications. The journal publishes original papers and review articles on the design, synthesis, characterisation and applications of optical materials. OPTICAL MATERIALS focuses on: • Optical Properties of Material Systems; • The Materials Aspects of Optical Phenomena; • The Materials Aspects of Devices and Applications. Authors can submit separate research elements describing their data to Data in Brief and methods to Methods X.