Anodic oxidation of niobium has been investigated in an electrolyte solution containing calcium phosphate and calcium acetate. The oxide layer morphology has been determined by combining 3D Atomic Force Microscopy images and cross-sectional Field Emission SEM measurements. The surface sensitivity of high-resolution X-ray Photoemission Spectroscopy has been exploited to evaluate the chemical composition of the outermost oxide surface, a key feature in view of implant development. Anodic Spark Deposition (ASD) results in the formation of micrometer-thick oxide layers showing a porous morphology suitable for osseointegration purposes. Increasing the maximum potential attained during oxidation leads to an increase of the oxide thickness and pore size accompanied by a noticeable surface enrichment with calcium and phosphorus. Remarkably, a maximal Ca/P ratio of 1.8 was achieved for anodization at 250 V, promising for osseointegration thanks to the similarity with hydroxyapatite stoichiometry. Parallel experiments performed on titanium under the same conditions indicated a maximal Ca/P ratio of 1.3 and pores of smaller dimensions. The comparative analysis suggests that niobium may represent a promising alternative to titanium to be explored for implant development.

已经在包含磷酸钙和乙酸钙的电解液中研究了铌的阳极氧化。通过结合3D原子力显微镜图像和横截面场发射SEM测量，确定了氧化物层的形态。高分辨率X射线光电子能谱的表面敏感性已被用来评估最外层氧化物表面的化学成分，这是考虑到植入物发展的关键特征。阳极火花沉积（ASD）导致形成了微米厚的氧化层，显示出适合骨整合目的的多孔形态。氧化过程中获得的最大电势的增加导致氧化物厚度和孔径的增加，并伴有钙和磷的明显表面富集。值得注意的是 在250 V的阳极氧化条件下，最大Ca / P比达到1.8，由于与羟基磷灰石化学计量的相似性，有望实现骨整合。在相同条件下对钛进行的平行实验表明，最大的Ca / P比为1.3，且孔的尺寸较小。对比分析表明，铌可能代表了有待开发植入物的钛的有前途的替代品。