Influence of chemical pressure effects on nonlinear thermal conductivity of intrinsically granular superconductors

Using a 2D model of capacitively coupled Josephson junction arrays (created by a network of twin boundary dislocations with strain fields acting as an insulating barrier between hole-rich domains in underdoped crystals), we study the influence of chemical pressure on nonlinear thermal conductivity (NLTC) of an intrinsically granular superconductor. Quite a substantial enhancement of NLTC is predicted when intrinsic chemoelectric field closely matches the externally produced thermoelectric field. The estimates of the model parameters suggest a realistic possibility to experimentally monitor this effect in non-stoichiometric superconductors.