Mechanism study of the Mn‐substituted magnesium borate: Decreased sintering temperature and improved dielectric property
Rui Peng, Yongcheng Lu, Yuanxun Li, Hua Su, Liang Shi, Guoliang Yu, Yuanming Lai, Qiang Zhao, Xiaolei Shi, Huaiwu Zhang
Abstract
Abstract The influence of manganese substitution on the sintering and dielectric properties of Mg 3 B 2 O 6 (MBO) was studied, and the detailed mechanism of variation was discussed using density functional theory calculations. The characterization method involved a network analyser, differential–thermal analyses, thermomechanical analyses, X‐ray diffraction, and scanning electron microscopy. Manganese substitution formed a two‐phase system (MBO and Mg 2 B 2 O 5 ), improved the dielectric property, densified the microstructure, lowered the activation energy, decreased the crystallite size, modified the band structure property, and strengthened the covalency of MgO 6 octahedron. The 7% mole substitution of manganese to magnesium improved the dielectric properties of MBO to 7.06 for ε r and 61 100 GHz at 15 GHz for Q × f , −54.8 ppm/°C for τ f . The intrinsic densification temperature decreased from 1350 to 1175°C with 97.7% relative density.