Role of interfacial nickel silicides in shaping magnetic anisotropy in nickel films grown on Silicon substrates.

Using different experimental techniques such as X-ray reflectivity, X-ray diffraction, X-ray photoelectron spectroscopy and magneto-optical Kerr effect (MOKE) microscopy, the structural and magnetic properties of Ni films grown on Si substrates are investigated. Various Ni-silicide phases are found to be formed at the Ni–Si interface as a function of depth following the sequence Ni-Ni 2 Si-NiSi-NiSi 2 from the nickel to silicon side. This has been explained in terms of the effective heat of formation and inter-diffusion of the elements at the interface. In-plane magnetic anisotropy of the system is investigated by measuring in-plane magnetization using MOKE microscopy. The film exhibits an uniaxial in-plane magnetic anisotropy. An anomalous behavior, i.e., the collapse of the hard axis, has also been observed. This anomaly has been explained in terms of the creation of V-state domains during the magnetization reversal process at the hard axis. Interestingly, in-plane magnetic anisotropy could not be found in a Ni film grown with a Pt buffer layer on the Si substrate. Ni-silicide phases could not be detected in this system. This may suggests that the formation of silicides and diffusion at the interface causes the atypical magnetic anisotropy in Ni–Si sample. • Impact of interfacial nickel silicide formation on the In-plane magnetic anisotropy of Ni thin film. • The collapse of hard axis is explained by the formation of V-state domains. • Formation of different Ni silicide like Ni 2 Si, NiSi and NiSi 2 forms at the Ni/Si interface. [ABSTRACT FROM AUTHOR]