中文摘要：

研究了传统固相反应法制得的MgLnGaO4（Ln=La,Nd,Sm）陶瓷相组成、显微结构、烧结性能与微波介电性能之间的关系。结果表明：通过添加不同稀土元素所得的MgLaGaO4和MgNdGaO4试样为单一正交钙钛矿结构;而MgSmGaO4试样形成的是A3B5O12型石榴石结构固溶体。当烧结条件为1420℃/4h时,MgSmGaO4陶瓷可获得最佳的微波介电性能,介电常数为12.599,品质品数为70657.16GHz（f=8.85GHz）,谐振频率温度系数为-7.2×10^-7/℃。

英文摘要：

MgLnGaO4 （Ln=La, Nd, Sm） ceramics were prepared by solid-phase reaction method. The relationships among their phase composition, microstructures, sintering characteristics, and microwave dielectric properties were studied. The results show that the MgLaGaO4 and MgNdGaO4 samples obtained by adding different rare earth elements have orthorhombic perovskite structures, while the MgSmGaO, sample is the A3B5O12-type garnet structure solid solution. When the MgSmGaO, sample is sintered at 1 420 ℃for 4h, the MgSmGaO4 ceramic has the best microwave dielectric properties. The dielectric constant is 12.599, the quality factor is 70657.16 GHz （f=8.85 GHz）, and the temperature coefficient of resonant frequency （rf） is -7.2×10^-7/℃.