Sr^(2+)置换改性Ca_(0.25)(Li_(1/2)Sm_(1/2))_(0.75)TiO_3陶瓷的微波介电性能研究

Microwave Dielectric Properties of Sr^(2+) Modified Ca_(0.25)(Li_(1/2)Sm_(1/2))_(0.75)TiO_3 Ceramics

采用固相法制备了(Ca1-xSrx)0.25(Li1/2Sm1/2)0.75TiO3(CSLST-x)(x=0～1/10)系列微波介质陶瓷材料,研究不同含量的Sr2+含量对该体系的相组成、烧结性能和微波介电性能影响。在x=1/22～1/10范围内,Sr2+的掺杂不会改变晶体的结构;在1175～1200℃烧结时,相同烧结温度下随着Sr2+含量的增加,介电常数εr增大,无载品质因数与谐振频率乘积Qf值降低;置换离子Sr2+的添加使该体系的烧结温度降低了近200℃,并保持良好的微波介电性能。其中,x=1/16的CSLST陶瓷在1200℃烧结,保温5h时具有较好的微波介电性能:εr=97.2,Qf=2490GHz,τf=14.74ppm/℃。

（Ca1-xSrx）0.25（Li1/2Sm1/2）0.75TiO3（CSLST-x）（x= 0-1/10） microwave dielectric ceramics were prepared by solid state reaction technique.The effect of Sr2＋content on the crystal structure,sintering properties and microwave dielectric properties of the ceramics were investigated.The results show that the crystal structure of the ceramics is not influenced by the Sr2＋ dopant in the range of 1/22-1/10.In the range of 1175-1200 ℃ sintering temperatures,the dielectric constant εr increases,and quality factor and resonance frequency （Qf） value of the product decrease as the Sr2＋ content increasing at the same sintering temperature.The sintering temperatures of the Sr2＋ modified ceramics are efficiently decreased by nearly 200 ℃ and keep good microwave dielectric properties.The sample of CSLST with x=1/16 sintered at 1200 ℃ for 5 h has excellent microwave dielectric properties：εr=97.2,Qf=2490 GHz,τf=14.74 ppm/℃.