Rare earth element-doped barium titanate giant dielectric ceramic material and preparation method thereof

Abstract

The invention provides a rare earth element-doped barium titanate giant dielectric ceramic material and a preparation method thereof, and belongs to the technical field of giant dielectric ceramic materials. A traditional solid-phase reaction method is adopted for preparation, a barium source, a titanium source and a Re source are weighed according to the chemical general formula Ba1-xRexTiO3, x is larger than or equal to 0.01 and smaller than or equal to 0.03, Re is one or two of La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er, drying is conducted after ball milling, air calcination and secondary ball milling are conducted, a PVA aqueous solution is added for granulation, and the mixture is pressed into a wafer. And after the wafer is sintered, annealing for 2-5 hours in a nitrogen environment, then polishing the sample, and coating silver electrodes on two surfaces to obtain a final sample. The giant dielectric ceramic material provided by the invention has a room temperature dielectric constant of more than 100000 and a dielectric loss of less than 0.05 at 1kHz, has relatively high dielectric stability in a certain temperature range, and can be applied to the field of single-layer ceramic capacitors.

Description

technical field [0001] The invention relates to the technical field of giant dielectric materials, in particular to a barium titanate giant dielectric ceramic material doped with rare earth elements and a preparation method thereof. Background technique [0002] In order to meet the rapid development of electronic device miniaturization and high energy density storage, the research of giant dielectric materials has become a very important issue. Giant dielectric materials usually refer to doped BaTiO 3 , SrTiO 3 and TiO 2 , and CaCu 3 Ti 4 o 12 and NiO 2 Wait. However, these systems have their own defects, such as CaCu 3 Ti 4 o 12 and NiO 2 The loss of the base dielectric material is very high (<0.1), TiO 2 The breakdown field strength of the matrix giant dielectric material is low, while the doped BaTiO 3 The base dielectric material has a strong temperature dependence due to the phase transition point between -90°C and 120°C, and doped SrTiO 3 The dielectr...

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Problems solved by technology

However, these systems have their own defects, such as CaCu 3 Ti 4 o 12 and NiO 2 The loss of the base dielectric material is very high (<0.1), TiO 2 The breakdown field strength of the matrix giant dielectric material is low, while the doped BaTiO 3 The base dielectric material has a strong temperature dependence due to the phase transition point between -90°C and 120°C, and doped SrTiO 3 The dielectric constant of the base dielectric material is low, these are problems that need to be solved urgently

[0003] TiO 3 Ceramics have attracted much attention due to their excellent dielectric properties, but there are still many shortcomings as a giant dielectric material. The biggest defect is that its dielectric constant has a strong temperature dependence.

Although it has a large dielectric constant (greater than 10) near the Curie point 3 ) and low loss (<0.015), but a ferroelectric phase transition (from tetragonal phase to cubic phase) will occur at the Curie point, which makes the dielectric constant drop sharply. Applications in the field of electricity

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