Mechanism study of the Mn‐substituted magnesium borate: Decreased sintering temperature and improved dielectric property

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.