- characteristics calculated for the ferromagnet-insulator-superconductor (F/I/S) tunneling junctions. Ferromagnet is an iron with bcc structure and the superconductor is Hg- high- superconductor . The normalized charge current is defined by (11), and the normalized voltage is defined by . (a), (b), and (c) on the first line are results calculated for the nonmagnetic phase, (d), (e), and (f) on the second line are for the electron configuration with , and (g), (h), and (i) on the third one are for that with . (a), (d), and (g) on the left column are results calculated for the case of coherent tunneling, (b), (e), and (h) on the central one are for the case of incoherent tunneling, and (c), (f), and (i) on the right column are for the case of WKB treatment. In (a), (d), and (g) calculated as the coherent tunneling, there are some regions in which the differential conductance is calculated as the negative value which is unreasonable. Moreover, also in (c) for the WKB case, the region of the negative differential conductance is found in the normalized voltage around . Note that all the calculations have been done for .