Effect of manganese and vanadium valences for the reliability of BaTiO3-based MLCCs

The valences of manganese and vanadium oxides in multi-layer ceramic capacitors (MLCCs), sintered under a reducing atmosphere, were investigated using electron paramagnetic resonance, the insulation resistance degradation was analyzed using impedance spectroscopy in highly accelerated life time tests to clarify the manganese and vanadium influence on both the electrical properties and microstructure of MLCCs. The Mn
²⁺
was stable in the reducing-atmosphere-sintered MLCCs, and formed a grain boundary. Vanadium mitigated the IR degradation and increased the reliability of the MLCCs. Although V
⁴⁺
was detected in the 0.20 and 0.30 mol% vanadium-added MLCCs, the electrical properties were dependant upon the other ions, e.g., V
³⁺
or V
⁵⁺
.