Doped perovskite barium stannate material with preparation method and application thereof
Disclosed herein is a doped perovskite barium stannate material, which has a chemical general formula of BaA x B x Sn 1-2x O 3 , where A is at least one of In, Y, Bi and La; B is at least one of Nb and Ta, and 0<x≤0.025. The doped perovskite barium stannate material disclosed in the invention has a high dielectric constant, low dielectric loss and good temperature-stability, and it can be used not only as low-frequency ceramic capacitor dielectrics, but also as microwave dielectric ceramics because of its excellent microwave dielectric properties, implying the potential application in the field of microwave communication. What's more, disclosed is a method to prepare the doped perovskite barium stannate material and the application of the doped perovskite barium stannate material in a low-frequency ceramic capacitor or microwave communication dielectric ceramics.
1. A preparation method of a doped perovskite barium stannate material, the doped perovskite barium stannate material has a chemical general formula:
BaA x R x Sn 1-2x O 3 ,
where A is In, Y, Bi, or La, or a mixture of two or more of these; R is Nb or Ta, or a mixture of both; and 0<x≤0.025,
wherein the preparation method comprises of the following steps:
(1) Weighing out a barium source, a tetravalent tin source, an A 3+ source and a R 5+ source, respectively, according to the chemical general formula;
(2) Mixing the above sources thoroughly and ball-milling, and then drying to obtain homogeneous mixed powder;
(3) Placing the mixed powder obtained in step (2) into an alumina crucible, and performing calcination treatment on the mixed powder to obtain calcined powder;
(4) Adding sintering aid, B 2 O 3 , to the calcined powder, and then ball-milling again and drying to obtain preliminary powder; and
(5) Pressing the preliminary powder obtained in step (4) to get pellets, followed by sintering the pellets to obtain the doped perovskite barium stannate material.
2. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein at least one of the following requirements (a) to (d) is satisfied:
(a) The barium source is BaCO 3 , Ba(NO 3 ) 2 , Ba(NO 3 ) 2 hydrates, BaSO 4 , BaSO 4 hydrates, Ba(OH) 2 , Ba(OH) 2 hydrates, Ba(C 2 H 3 O 2 ) 2 , Ba(C 2 H 3 O 2 ) 2 hydrates, Ba 3 (PO 4 ) 2 , or Ba 3 (PO 4 ) 2 hydrates, or a mixture of two or more of these;
(b) The tin source is SnO 2 ;
(c) The A 3+ source is A 2 O 3 , A 2 (C 2 O 4 ) 3 , A 2 (C 2 O 4 ) 3 hydrates, A(NO 3 ) 3 , A(NO 3 ) 3 hydrates, A 2 (SO 4 ) 3 , A 2 (SO 4 ) 3 hydrates, A 2 (CO 3 ) 3 , A 2 (CO 3 ) 3 hydrates, A(C 2 H 3 O 2 ) 3 , or A(C 2 H 3 O 2 ) 3 hydrates, or a mixture of two or more of these; and
(d) The R 5+ source is R 2 O 5 .
3. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein in step (3), the calcination treatment comprises heating to a temperature in a range from 1000° C. to 1200° C. for 3 hours with a heating rate of 4° C./min to 6° C./min, and naturally cooling down to room temperature.
4. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein in step (4), a weight ratio of the sintering aid, B 2 O 3 , to the calcined powder is 0.5% to 5%.
5. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein the preparation method further comprises step (6) after step (5):
performing surface polishing treatment on the doped perovskite barium stannate material obtained in step (5) and then annealing.
6. The preparation method of a doped perovskite barium stannate material of claim 5 , wherein the annealing comprises heating to a temperature in a range from 1000° C. to 1500° C. for 1 to 24 hours in air with a heating rate of 1.5° C./min to 15° C./min, and then naturally cooling down to room temperature.
7. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein in step (5), the sintering comprises heating to a temperature in a range from 1300° C. to 1500° C. for 6 to 24 hours in air with a heating rate of 4° C./min to 6° C./min, and then naturally cooling down to room temperature.
8. The preparation method of a doped perovskite barium stannate material of claim 1 , wherein in step (3) and step (4), the ball-milling is carried out for at least 12 hours with yttrium-stabilized zirconia beads as a medium and ethanol and/or acetone as solution.