Spin-caloritronic transport in superconductor-ferromagnet tunnel structures

We investigate the effect of an exchange field and spin-flip scattering on the pair potential and the spin Seebeck coefficient of superconductor (S) - ferromagnet (F) hybrid structures using the Green's function method. Such structures have been predicted to show giant charge Seebeck coefficient. In the absence of spin-flip scattering, the pair potential of the S has been studied for different values of the exchange field. We show that the normal to S phase transition with decreasing temperature, changes character from second to first order above a certain value of exchange field. The density of states in energy, and spin Seebeck coefficient as a function of temperature have been computed for several values of spin-flip scattering time. We show that spin-flip scattering limits the enhancement in the spin Seebeck coefficient in realistic settings.