掺杂对PMN铁电陶瓷烧结工艺和介电性能的影响

使用常用的两步法，研究了基体掺杂不同物质对ＰＭＮ陶瓷的烧结工艺和介电性能的影响．经研究发现，当掺杂 １ｍｏｌ％Ｌｉ_２Ｏ时，可以实现 ９５０～１０００℃左右的中温烧结，材料的常温介电常数和介电损耗分别为 １３５００和 ０．５５％，都优于纯 ＰＭＮ．当掺杂 ２ｍｏｌ％时，可以将烧结温度降到８００～９００℃的低温烧结范围，且介电损耗明显下降．分析结果表明；材料的显微结构良好，材料的致密化程度较高．另外，掺加 Ｌｉ_２Ｏ和 ＳｒＯ可以分别稍微减小和增加材料的弥散相变程度．同时本文还研究了ＰＭＮ陶瓷的微观结构和介电弛豫的情况．

Effects of Doping on Sintering Process and Dielectric Properties of PMN Ceramics

Sintering process and dielectric properties were studied by adding a small amount of different dopants into PMN ceramics using normal two-step method. When doped with 1mol% Li₂O, the sintering temperature of PMN can be reduced to 950～1000℃. The dielectric constant and loss tangent of this material are 13500 and 0.55% respectively, which are better than those of pure PMN. When doped with 2mol% SrO, low temperature sintering about 800～900℃ can be attained while its loss tangent at room temperature reduced to only 0.36%. Analysis results show that the materials have good microstructures and are highly condensed. Anyhow, doped with Li₂O and SrO can slightly lower and enhance the extent of diffuse phase transition (DPT).