Sintering characteristics and microwave dielectric properties of ultralow-loss SrY2O4 ceramics

A SrY2O4 microwave dielectric ceramic suitable for 5G systems is synthesised via a solid-state reaction in a sintering temperature range of 1425–1525 °C. X-ray diffraction patterns and Rietveld refinement analysis show that the ceramic has an antispinel orthorhombic crystal structure belonging to the Pnma space group. Scanning electron microscopy images show that the ceramic particles are closely connected, the grain boundaries are clear, and the particles are uniform at the optimal sintering temperature of 1475 °C. The optimal microwave dielectric performances are εr = 14.78, Q × f = 84090 GHz, τƒ = −14.98 ppm/°C. The relatively low dielectric constant, high Q × f value, low τƒ value, and easily available raw materials indicate that it is a good choice for 5G equipment.