LAUSR

Abstract In current study, only 5 mol% Mn 2+ was applied to fabricate high performance microwave dielectric ZnGa 2 O 4 ceramics, via a traditional solid state method. The crystal structure, cation distribution and microwave dielectric properties of as-fabricated Mn-substituted ZnGa 2 O 4 ceramics were systematically investigated. Mn 2+ -substitution led to a continuous lattice expansion. Raman, EPR and crystal structure refinement analysis suggest that Mn 2+ preferentially occupies the tetrahedral site and the compounds stay normal-spinel structure. The experimental and theoretical dielectric constant of Zn 1- x Mn x Ga 2 O 4 ceramics fit well. In all, this magnetic ion, Mn 2+ , could effectively adjust the τ f value to near zero and double the quality factor from 85,824 GHz to 181,000 GHz of Zn 1- x Mn x Ga 2 O 4 ceramics at the meantime. Zn 1- x Mn x Ga 2 O 4 ( x  = 0.05) ceramics sintered at 1400 °C for 2 h exhibited excellent microwave dielectric properties, with e r = 9.7(@9.85 GHz), Q  ×  f  = 181,000 GHz, tanδ  = 5.44 × 10 −5 ,and τ f = − 12 ppm/°C.