抄録
Doping effect of rare-earths on the temperature-capacitance characteristics of MLCCs with Ni electrodes has been investigated for BaTiO3-MgO-Rare-earth system. Temperature dependence of capacitance became smaller with smaller radii ions such as Ho, Er, Tm, Yb, and Lu. Especially, Tm, Yb, and Lu were effective dopants to depress the temperature dependence of capacitance. The Curie temperature also shifted toward higher temperatures by the doping of smaller ionic radii rare-earth elements. On the other hand, temperature dependence of capacitance became larger and the insulation resistance became lower by the doping of larger ionic radii rare earth elements such as Tb and Gd. It is clear that ionic radius of rare-earth dopants is an important factor to control the temperature-capacitance characteristics as well as improving the reliability. Ni electrode MLCCs with X8R characteristics specification for automotive use have been developed newly using rare-earth dopant having smaller ionic radii such as Tm, Yb, Lu.
