The structural characteristics and microwave dielectric properties of Ti4+ doped CaMgSi2O6 ceramics.

The effect of Ti substitution on microwave dielectric properties and structural characteristics of CaMgSi 2 O 6 ceramics synthesized via solid-state reaction method was investigated by XRD, XPS, Raman spectroscopy, SEM, EDS, Rietveld refinement, P–V-L theory and bond valence theory. XRD patterns indicated that CaTiO 3 was gradually formed with the increase in Ti content. The permittivity was closely related to ionic polarizability, which was confirmed by Raman shifts. Quality factor (Q × f) and temperature coefficient of resonant frequency (τ f) were considerably affected by lattice stability. Moreover, lattice energy and cation ordering of CaMgSi 2 O 6 influenced Q × f , while cation bond valence affected the τ f value. Improved microwave dielectric properties were achieved with high lattice energy and appropriate bond valence for well-densified CaMgSi 1.95 Ti 0.05 O 6 ceramics with specific values of Q × f = 80774 GHz (±2578 GHz; @13.47 GHz, tan δ = 1.67 × 10−4), ε r = 7.94 (±0.208), and τ f = −58.56 ppm/°C (±2.65 ppm/°C) with high relative density (ρ r = 96.9%). [ABSTRACT FROM AUTHOR]