In the framework of scattering theory, we study the tunneling conductance in a system including two junctions, ferromagnetic metal/normal metal/ferromagnetic superconductor, where ferromagnetic superconductor is in spin-singlet -wave pairing state. The non-magnetic normal metal is placed in the intermediate layer with the thickness ( ) which varies from 1？nm to 10000？nm. The interesting result which we have found is the existence of oscillations in conductance curves. The period of oscillations is independent of FS and FN exchange field while it depends on . The obtained results can serve as a useful tool to determine the kind of pairing symmetry in ferromagnetic superconductors. 1. Introduction In this paper we have studied tunneling conductance in a two-junction system with structure of ferromagnetic metal/normal metal/ferromagnetic superconductor. A constant spin-singlet -wave pairing potential and a constant exchange field are our presuppositions for the ferromagnetic superconductor. The main goal of this paper is to show the existence of oscillations in conductance curves with period of oscillations independent of FS and FN exchange field but dependent on . The structure of this paper is as follows. In Section 1 a historical view of the under study subject together with a short report of the results is presented. In Section 2 the model and the theoretical framework of our system are studied. In Section 3 we have presented and discussed the results of the paper. For a long time, coexistence of superconductivity and ferromagnetism has been a challenging issue in the history of superconductivity. It was believed that superconductivity and ferromagnetism were two opposite phenomena and coexistence between them was impossible. The view toward ferromagnetism and superconductivity changed when ferromagnetic superconductors were discovered in 2000-2001. The discovery of superconductivity in some ferromagnetic materials such as [1], [2], and [3] has attracted much attention in the field of superconductivity. The questions are mostly raised about the mechanism of cooper pairing in ferromagnetic superconductors. At the first glance, it seems that the pairing symmetry of such materials should be spin triplet equal spin pairing. But some research groups have shown that one could not ignore spin-singlet -wave opposite spin pairing [4–11]. For example, in [7], Singh and Mazin by calculating the electronic structure, as well as the zone center phonons and their coupling with electrons, have shown that has a spin-singlet -wave pairing state. Also, in [8], due to
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