Improved sintering and microwave dielectric properties of Li2CaSiO4 ceramic with magnesium atom substitution

The influence of Mg2+-ion substitution on the sintering and microwave dielectric properties of Li2CaSiO4 ceramic was investigated using the traditional solid-state reaction method and density functional theory. X-ray diffraction, scanning electron microscopy, Raman spectrometry, network analysis and simultaneous thermal analysis were used to characterise the macro properties. The replacement of Ca2+-ion with Mg2+-ion led to the transformation of dodecahedron into tetrahedron. In addition, the bond length and bond population related to the calcium site decreased. The atom vibration and microstructure characteristics were modified due to the lattice distortion. The densification temperature decreased from 1000 degrees C to 925 degrees C. The relative density increased from 70% to 80.5%. The dielectric properties were improved, that is, epsilon(r) = 5.63, tan6 = 0.0019 at 8 GHz as 4% (molar ratio) Ca2+-ions were replaced by Mg2+-ions.