Nucleation-promoted L10 ordering in FePt thin films with ultrasmall grain size

FePt thin films with an ultrasmall grain size of similar to 3.4 nm were successfully prepared by employing a relatively high sputtering pressure of 4 Pa that produces deposited target atoms or clusters with low energy. The L1(0) ordering in the FePt thin films is dominantly dependent on the nucleation of ordered domains rather than their growth which is usually observed in the films with relatively large grain size. The nucleation-promoted L1(0) ordering makes a reduction in grain growth and thus yields the L1(0)-FePt thin films with a uniform and small grain size below 10 nm.