It depends on the properties of the materials of the added nanoparticles.

The question here is: If the linear rule of mixture of composites is applicable.

It could be difficult for one to make generilization regarding the effect of nanoparticles on specicific capacitance of superconductors. This has to do with the fact that each nanoparticle has its own chemistry or propertie hence, it affects the superconductor in a specific way. So, it could be helpful if a disclosure will be made regarding the composition of the nanoparticles as well as the type of the superconductor under consideration.

Best regards

There may be a change in the dielectric properties.

Dear Hanan Rahal,

give us, please, some refs or data about the (astonishing) postulation[1] in your question ?

1. Quot :"...sometimes decrease the specific capacitance(!) of superconductors(!) ?."

Dear Hanan Rahal,

The fluctuations in the Phase Transition state with temperature influence the dielectric response of the superconductors, also, the magnetic, metallic, magnetic oxide and insulating types of inserted nanoparticles differently affect the conductivity, dielectric nature and hence the overall capacitance.