Mn和Zr共掺杂钛酸锶钡/氧化镁复合陶瓷材料的微结构和介电性能

通过固相反应法制备Mn、Zr共掺杂钛酸锶钡/氧化镁陶瓷粉体,经干压成型后在空气气氛中于1450℃烧结4h,通过扫描电子显微镜和X射线衍射研究了ZrO2和MnO2共掺杂的Ba0.6Sr0.4TiO3/MgO复合陶瓷材料的微结构和介电性能。结果表明:ZrO2可以显著降低材料的介电常数和介电损耗,有效提高了陶瓷材料的温度稳定性;随ZrO2添加量的增加,体系的晶胞参数略有增加,MgO在钛酸锶钡中以独立相的形式存在;制备出的BST铁电陶瓷材料的25℃相对介电常数较低(εr<110),介质损耗小于1.0×10–3(在频率为10kHz时),温度系数小于6.012×10–3,可调性大于20%(8.0kV/mm),适用于制作移相器。

Crystal Structure and Dielectric Properites of Ba0.6Sr0.4TiO3/MgO Ceramics Doped with ZrO2 and MnO2

ZrO 2 and MnO 2 co-doped Ba 0.6 Sr 0.4 TiO 3 /MgO precursor powder was synthesized by solid reaction method. The precursor was sintered in air at 1450 ℃ for 4 h. The crystal structure and dielectric properties of Ba 0.6 Sr 0.4 TiO 3 /MgO ceramics doped with ZrO 2 and MnO 2 were investigated by scanning electron microscopy and X-ray diffraction, respectively. The results show that the relative dielectric constant and dielectric loss of the barium strontium titanate (BST) ceramics decrease, the temperature stability and the crystal cell parameter of BST ceramics increase and MgO presents in BST as a separate phase with the increase of ZrO 2 doping. The BST ferroelectric ceramic material with a low dielectric constant (ε r <110) at 25 ℃ andthe dielectric properties (i.e., dielectric loss tan δ<1.0×10 –3 at 10 kHz, temperature coefficient <6.012 × 10 –3 and tunability >20% at 8.0 kV/mm) suitable for phase shifter was prepared.