Investigation into the effect on the property of Na₂WO₄ ceramic prepared by the further modified solid-state reaction method

After a long time of exploration, the solid-state reaction method is further modified. In the granulation process, 10 % isopropanol is added into ethanol to increase the viscosity. More than that, the green body of the ceramic is placed into the isostatic press and pressed at 200 MPa for 3 min again after being kept in the muffle furnace at 120 °C for 1 h. The modified solid-state reaction method further improves the sintering property of the Na2WO4 ceramic, which increases the dielectric property of the ceramic sample greatly. Besides, the granulation problem, the bubble problem and the problem in demoulding process are solved. The substitution of ethanol and isopropanol for polyvinyl ethanol (PVA) completely avoids the residue of PVA in the ceramic sample and increases the fluidity of the ceramic particles in the granulation process. As a result, the Na2WO4 ceramic can be sintered well at 560 °C with a relative permittivity of 5.82, Q × f value of 131300 GHz and a temperature coefficient of resonant frequency (TCF) value of −56.2 ppm/°C in this work. The modified solid-state reaction method is a good substitute for the conventional solid-state method.