Inverse Proximity Effect Validates
Dielectric Constant's Influence

27 September 2025
UPDATED 12 Oct. 2025
Superconductors.ORG

        Recently Superconductors.ORG reported a direct link had been found between dielectric constant (relative permittivity K) of lattice substructures and the transition temperature (Tc) of a superconductor. Now, it's been found that the inverse proximity effect (IPE) can achieve the same result in some high temperature superconductors — like BSCCO. High permittivity ferroelectrics such as barium-titanate (BTO) can promote the Tc of BSCCO by simply being in close contact. While the dielectric constant of BTO is a function of temperature and frequency, it can be as high as 7000. In the two magnetization plots at page top a 50-50 mix of BSCCO powder(1) and barium-titanate powder(2) are shown. This adjunct increased the Tc of Bi-2223 by more than 15 degrees — without any sintering.(3)



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       These plots resulted from twin Hall effect sensors configured to generate a transient at the start and at the completion of the Meissner transition. As can be seen, both mixes make the transition to a superconductive state across about 8 degrees Kelvin. This is consistent with published data on Bi-2223. Normally, industrial grade BSCCO begins its Meissner transition at 108K and is fully superconductive by 100K. This pellet was of slightly lower quality after being in storage for some years.

       A number of tests were performed using this configuration. Then those plots with the highest and lowest Tc's were discarded and the remaining 3 from each group were evaluated. Powder from the same BSCCO disk was used in all the tests. The average Tc improvement was found to be around 15 degrees. And the point at which diamagnetism first appears improved by an average of 20 degrees. This is the mysterious "pseudogap" region where electrons begin to pair up. See the below zoomed plots.


         

       In the below test BTO was laminated onto both sides of a second BSCCO disk and direct resistance tests were performed. The results are comparable to the mix tests. Resistance begins to drop at the temperature where diamagnetism began to appear in the magnetization tests. Then the resistance curve flattens near where the Meissner transition begins.

                    

NOTE:   The Hall effect sensors employed do not generate a magnetic field. They operate within the 0.55 - 0.60 Oe ambient field from earth's magnetic field. So it is not known how strong a magnetic field the inverse proximity effect will exclude before quenching. Additional tests will need to be performed. Nonetheless, the 15 degree improvement in Tc confirms the correlation between permittivity and Tc is indeed real and could be exploited.


1. A commercial-grade BSCCO disc was obtained from Colorado Superconductor, Fort Collins, CO., and then ground into a fine powder.

2. The BTO was barium-titanate powder (BaTiO3, 99.9% purity, 325 mesh), obtained from Chemsavers, Bluefield, VA.

3. Testing temperatures were determined using an Omega type "T" thermocouple. The magnetometer employed twin Honeywell SS94A1F Hall-effect sensors with a tandem sensitivity of 50 mv/Gauss.

E. Joe Eck
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