摘要 |
<p>An electrode material for capacitor comprising metal selected from tantalum metal, niobium metal and tantalum-niobium composite metal and a dielectric layer formed on the metal, wherein the dielectric layer is obtainable (i) by reacting the above-mentioned metal having a metal oxide surface layer, with an alkaline solution to convert at least a part of the metal oxide layer into at least one metal acid compound selected from a tantalic acid compound, a niobic acid compound and a composite material of tantalic acid compound with niobic acid compound, or (ii) by subjecting the above-mentioned metal as anode, to electrolytic oxidation in an alkaline solution to form at least one metal acid compound selected from a tantalic acid compound, a niobic acid compound and a composite material of tantalic acid compound with niobic acid compound. A capacitor with this electrode material is characterized as having a large capacitance while maintaining good leak current characteristics.</p> |