Method for preparing barium titanate compounds

Abstract

The invention relates to a novel method for preparing barium titanate compounds, namely a hydrothermal-gel method, which combines the advantages of traditional hydrothermal method and sol-gel method and combines the characteristics of the hydrothermal synthesis method of mild reaction conditions and good repeatability and the characteristics of the sol-gel method that quantitative trace elements can be uniformly added and uniform mixing in molecular level can be realized. The method has the main advantages that firstly, the method is simple and easy to operate, has good repeatability, and has no strict requirements on solution acidity, moisture content, gelation temperature and gelation time in gelation process; secondly, the gelation speed is high, the quality of the gel is good, and the calcined powder granules are uniform and thin; thirdly, the method has low requirement on reaction conditions, thus being applicable to modifying barium titanate by doping by most metal ions; fourthly, by controlling the use level of metal ions, the doping amount of metal ions substituting titanium ions or barium ions in the barium titanate can be well regulated and controlled.

Description

technical field [0001] The invention relates to a method for preparing barium titanate compounds. Background technique [0002] Barium titanate (BaTiO 3 ) are widely used in the preparation of electronic ceramic components such as thermistors, stack capacitors and electro-optical devices due to their excellent ferroelectric, dielectric, piezoelectric and pyroelectric properties. In recent years, BaTiO with a tetragonal structure 3 Multilayer ceramic capacitors (MLCC) can meet the requirements of miniaturization, integration and surface mounting of electronic circuits, and the market demand is increasing day by day. In addition to the above-mentioned wide application in ferroelectric, dielectric, piezoelectric and ceramic materials, barium titanate has also been well developed in the field of photocatalysis. Due to the increasingly serious environmental and energy problems in recent years, people have to find new methods that can solve both environmental pollution and res...

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Problems solved by technology

The solid-phase synthesis method generally uses barium oxide or carbonate and titanium dioxide, and the calcination temperature must reach above 1000°C to obtain barium titanate, and the temperature has a great influence on the structure and purity of barium titanate ; while the conventional sol-gel method has great requirements on the pH, water content and gel temperature of the solution, and the probability of gel is relatively low; Salt and titanium salt are prepared in proportion to the precursor, and an appropriate amount of strong base is added to the precursor as a mineralizer to adjust the pH of the reaction solution, and the prepared precursor is placed in a hydrothermal reactor to control the appropriate reaction Temperature, pressure and reaction time are used for hydrothermal reaction, but there are high requirements for hydrothermal temperature and hydrothermal time, and the hydrothermal time is generally more than 2 days, and fewer samples are obtained at the same time; although the co-precipitation method is relatively simple to operate , but the prepared sample has a larger particle size, more impurities, lower product purity, and is prone to agglomeration

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