Structural dependence of microwave dielectric properties of Ca3MgSi2O8 ceramics

This work focuses on the relationship between structure and microwave dielectric properties of Ca3MgSi2O8 ceramic via Rietveld refinement, excluded porosity calculation model, complex chemical bond theory, and harmonic oscillator model. A merwinite phase with P21/c space group is confirmed based on analysis of XRD patterns. The permittivity calculated by refractive-ionicity Eq. (12.33) is within 2% of the measured value (12.56). The Ca-O and Si-O bonds play a crucial role in the dielectric constants and dielectric loss, respectively. The temperature coefficient is related to oxygen octahedron distortion [MgO6]. The infrared spectrum is carried out to analyze intrinsic dielectric properties, which indicates the contribution of the active modes in the far-infrared range to the intrinsic permittivity and loss is dominant.

Automated summary

This study investigates the relationship between structure and microwave dielectric properties of Ca3MgSi2O8 ceramic using various methods, and identifies the crucial role of Ca-O and Si-O bonds in the dielectric performance.