I'm not sure some of the suggested compounds would work.

I assume the OP is interested in maintaining a very high dielectric
constant -- at least, that's a common reason for using barium titanate.
The presence of even tiny gaps between particles will drastically lower
the overall dielectric constant, for the same basic reason (substituting
electric for magnetic fields) that an air gap in a magnetic path
consisting of otherwise high permeability material will drastically
lower the overall permeability. So what's required is a compound that
allows the barium titanate particles to contact each other. I don't know
what kind of binder might do this, but it seems to me it would have to
be something that shrinks as it dries or cures, like conductive epoxy
binder. Conductive epoxy binder pulls the gold or silver particles
together when it cures to get good electrical conductivity.

I thought that capacitors and the like which use barium titanate were
fired into a homogeneous ceramic.

Roy Lewallen, W7EL