Nanostructured SmCo₅ Thin Films with Perpendicular Anisotropy Formed in a Wide Range of Sm–Co Compositions

In this work, we prepared SmCo₅ thin films with (000l) texture exhibiting perpendicular anisotropy in a wide range of Sm _x Co_100−x compositions (x = 13.2∼37.0) on Cu/Ta underlayers. At a composition of Sm_16.7Co_83.3(SmCo₅), the SmCo₅ film exhibits a maximum perpendicular coercivity of 18.2 kOe, which is attributed to a good crystallinity and an excellent (000l) texture. The SmCo₅ (000l) peaks are shifted to smaller angles compared to the standard powder sample which indicates the formation of a SmCoCu alloy through Cu diffusion. The EDX result for this sample gives a composition of SmCo₃Cu_2.1 which confirms Cu diffusion into the SmCo₅ layer. TEM image shows that SmCo₅ film is well crystallized with a grain size of 50 nm.