A transfer-function approach to the interpretation of relaxation spectra of second-order cross-effects in material science

The interpretation of relaxation spectra of second-order cross-effects is a problem that arises in some branches of materials science when coupling between thermal, mechanical and dielectric quantities is investigated. In this article, a transfer-function approach is combined with thermodynamics to treat this problem in a systematic way. Using quadratic electromechanical interaction as an example, an illustration is given of how an approximated expression for the relaxation strength can be obtained. The method presented is an extension of results on the thermodynamics of first-order coupling given in the literature