Effect of Mn Substitution on the Dielectric Constant and Breakdown Voltage of Anti-ferroelectric PLZT

초록

Anti-ferroelectric (PbLa)(ZrTi)O-3 (PLZT) is a promising material for use in multilayer ceramic capacitors (MLCCs) for electric vehicles, as its dielectric and polarization properties are enhanced under high electric fields. To facilitate the commercialization of Cu-MLCCs, sintering in a reduction atmosphere is necessary. In this study, the effect of adding Mn ions in varying concentrations (ranging from a small amount to an excess of 2.0 mol.%, 3.0 mol.%, 5.0 mol.%, 10.0 mol.%, and 20.0 mol.%) on the dielectric constant and breakdown voltage was investigated to understand their behavior under high electric fields. Regardless of the amount of Mn ions added, a single perovskite structure with no secondary phase was observed. These oxygen vacancies originated from the ions occupying the B-site in the perovskite structure, thereby influencing the dielectric properties and breakdown voltage. Interestingly, the breakdown voltage improved significantly, reaching up to 8.0 kV/mm, and no phase transition to the ferroelectric state occurred, regardless of the amount of Mn ions substituted. Overall, it was evident that the anti-ferroelectric properties of PLZT were well maintained.

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