Li3Mg2SbO6-based microwave dielectric ceramic material easy to sinter and with high q value, and preparation method therefor

A preparation method for a Li3Mg2SbO6-based microwave dielectric ceramic material, comprising the following steps:

• (1.1) preparing Li3SbO4 powder from Li2CO3 and Sb2O3 with a purity of 99% according to a chemical ratio of Li3SbO4;
• (1.2) mixing the Li3SbO4 powder uniformly, and mixing the Li3SbO4 powder by a wet milling method for 8 hours with pure water as a dispersing agent and a zirconium oxide ball (with a diameter of 3-15 mm) as a ball-milling medium to obtain a first milled product, wherein a weight ratio of the Li3SbO4 powder to the pure water to the zirconium oxide ball is 1:2:1.5;
• drying the first milled product at 120° C. after discharging;
• after passing the first milled product through a 80-mesh sieve, heating the first milled product from room temperature to 900° C. at a heating rate of 2° C./min, and conducting a heat preservation for 4 hours to prepare a Li3SbO4 microwave dielectric phase;
• (2.1) preparing a powder mixture from MgO, ZnO, and the Li3SbO4 microwave dielectric phase according to a chemical ratio of a molecular formula of Li3(Mg1-xZnx)2SbO6 (0.02≤x≤0.08), the MgO and the ZnO each has a purity of 99%;
• (2.2) uniformly mixing the powder mixture prepared in step (2.1), mixing the powder mixture by the wet milling method for 8 hours with the pure water as the dispersing agent and the zirconium oxide ball (with a diameter of 3-15 mm) as the ball-milling medium to obtain a second milled product, wherein a weight ratio of the powder mixture to the pure water to the zirconium oxide ball is 1:2:1.5;
• drying the second milled product at 120° C. after discharging, passing the second milled product through a 80-mesh sieve, and adding an organic adhesive to the second milled product at a weight ratio of 6-10 wt % to obtain a third mixture;
• conducting a granulation to the third mixture to obtain a granulated mixture;
• after passing the granulated mixture through a 120-mesh sieve, pressing the granulated mixture into a cylindrical green body with a diameter of 10-12 mm and a height of 5-6 mm, and putting the cylindrical green body into a muffle furnace for sintering in air at 1325° C. for 5 hours to prepare a sintered Li3(Mg1-xZnx)2SbO6 microwave dielectric ceramic;
• and
• (2.3) polishing two surfaces of the sintered Li3(Mg1-xZnx)2SbO6 microwave dielectric ceramic to prepare a finished product to be tested.