| 摘要 |
PURPOSE:To inexpensively obtain a sensor showing an accurate air/fuel ratio output characteristic at low temp., by reducing the amount of the sintering aid component of an element main body in the surface thereof as compared with a cut surface thereof. CONSTITUTION:As an oxygen ion conductive solid electrolyte material used in the formation of an element main body, a material prepared by compounding a predetermined stabilizer, for example, yttrium with zirconia is used. The molded body becoming the element main body having a predetermined shape is formed using said material and baked to predetermined temp. for a predetermined time to obtain the element main body. Predetermined chemical treatment is applied to the surface of the obtained element main body and the sintering aid component present in the surface thereof, for example, the SiO2 component therein is reduced or removed and the amount of the sintering aid component in the surface of the element main body is reduced as compared with that in the element main body. In order to reduce or remove the sintering aid component present in the surface of the element main body, a method for treating the element main body with an aqueous acid solution of HF or HCl or a method using an aqueous alkali solution of NaOH is adapted. |
