Niobium Oxide Films with Variable Stoichiometry: Structure, Morphology, and Ultrafast Dynamics
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Niobium oxide can be stabilized in three distinct stoichiometries, each exhibiting unique physicochemical properties relevant to various technological applications. This study presents a novel procedure for fabricating niobium oxide films and tuning their stoichiometry among the three most stable oxide phases. Starting with a magnetron-sputtered film predominantly composed of Nb 2 O 5, its structure and stoichiometry are optimized through thermal treatment in an O 2 /N 2 flux. A vacuum reduction treatment transforms the as-grown film into the NbO phase, which can then be reoxidized under controlled oxygen partial pressure to achieve the NbO 2 phase. The films are characterized in terms of surface composition using X-ray photoemission spectroscopy, structure through X-ray diffraction, optical properties via UV–vis spectrophotometry, and morphology using scanning electron microscopy. Additionally, we show that X-ray absorption near-edge spectroscopy at the Nb K-edge, performed with X-ray free-electron laser radiation, can provide insights into the electronic structure and subsurface stoichiometry of the films. The ultrafast mechanisms underlying photoinduced processes in NbO 2 are also discussed.
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4409586179