Electrically conductive oxide sintered compact, member for electrical conduction, and gas sensor

A gas sensor, characterized by having an electrode formed of a conductive oxide sintered body which contains a primary phase formed of a perovskite oxide containing at least La, Fe, and Ni;

• and a secondary phase formed of an La4M3O10 phase or an La3M2O7 phase (M=Co, Fe, Ni), wherein:
• the conductive oxide sintered body has a conductivity of 300 S/cm or higher at room temperature,
• the conductive oxide sintered body does not contain an NiO phase, and
• the conductive oxide sintered body is represented by formula:
• LaaCobFecNidOx
• (a+b+c+d=1, 1.25≤x≤1.75), and a, b, c, and d satisfy the conditions:
• 0.487≤a≤0.512,
• 0≤b≤0.200,
• 0.050≤c≤0.230, and
• 0.200≤d≤308.