According to one embodiment, a magnetoresistive effect head includes a magnetically pinned layer having a direction of magnetization that is pinned, a free magnetic layer positioned above the magnetically pinned layer, the free magnetic layer having a direction of magnetization that is free to vary, and a barrier layer comprising an insulator positioned between the magnetically pinned layer and the free magnetic layer, wherein at least one of the magnetically pinned layer and the free magnetic layer has a layered structure, the layered structure including a crystal layer comprising one of: a CoFe magnetic layer or a CoFeB magnetic layer and an amorphous magnetic layer comprising CoFeB and an element selected from: Ta, Hf, Zr, and Nb, wherein the crystal layer is positioned closer to a tunnel barrier layer than the amorphous magnetic layer. In another embodiment, a magnetic data storage system includes the magnetoresistive effect head described above.