When surface modifying high K ceramic particles like BT, BST or BZT for use in a high k ceramic/polymer composite film, some researchers say they get higher permittivity in the final film when the particles' surfaces are modified with, for example, an acid like gallic acid or phthalic acid. At the same time, other researchers say a low ph causes barium to dissolve from the particles' surfaces and they talk like it is a bad thing and say the ph needs to be kept higher? Who is right?
As per my knowledge, the dielectric property is not coming from the surface of the ceramic or composite. It depends on various parameters, like sintering procedure, preparation method of the ceramic or composites, grain or particle size, and some other.
In your case, in which method have you prepared this materials.
BT is a ferroelectric inorganic compound with piezoelectric properties and photorefractive effect. Generally, the appearance of BT is white powder. However, when large crystals are formed, BT becomes transparent. BT has the advantage of high dielectric constant and replaces lead zirconate titanate in the field of piezoelectric sensors, capacitors and high power energy storage devices. However, the fabrication of BT products requires high temperature sintering, and the porosity of ceramics greatly affects the dielectric properties of BT products.
Thanks but I'm well aware of what BT is already. Companies sell high k ceramic particles embedded in polymers to make a composite film rather than sintering into dense films of only the high K ceramics. Many researchers study how to make even better composite films.
Here is one example:
Article Effect of the Modifier Structure on the Performance of Bariu...
They are getting good results with acidic surface modifiers of their BT particles yet other researchers are saying not to go acidic because it causes Barium ions to come off the BT particles' surfaces and they act like that is a bad thing.
So my question is who is more correct and why?
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