Influência dos eletrólitos fosfato de sódio (Na3PO4), hidróxido de amônio (NH4OH) e ácido fosfórico (H3PO4) nas propriedades morfológicas dos filmes de óxido de nióbio obtidos por anodização eletrolítica

Abstract

Niobium, widely used in industry due to its properties, can form oxide layers through electrolytic anodizing. However, the specific influence of anodizing conditions on the properties of oxide layers has not yet been fully understood. Expanding this understanding has the potential to contribute to the development of new materials with enhanced properties for specific applications. The influence of electrolyte types on the morphological properties of niobium oxide films obtained by electrolytic anodizing was investigated. Sodium phosphate, ammonium hydroxide, and phosphoric acid solutions at concentrations of 0.1 M, 0.5 M, and 1 M were tested in the anodizing of niobium samples at 80 V and 150 V. Analysis by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy revealed that niobium oxide films were successfully obtained in phosphoric acid and sodium phosphate solutions, with greater regularity observed at higher concentrations and electrical voltages. However, anodizing in ammonium hydroxide solutions did not result in the formation of niobium oxide films at both electrical voltages. The composition and concentration of the electrolytes influence the feasibility of the electrolytic anodization process and the dielectric properties of the formed films. The concentration of the electrolytes directly affects their conductivity and the behavior of the reactions