Influence of growth parameters on the perpendicular magnetic anisotropy of [Co/Ni] multilayers and its temperature dependence

[Co/Ni] multilayer films are grown in various conditions to study the influence of growth parameters on the anisotropy of the films in order to optimize the perpendicular uniaxial anisotropy. These multilayers are expected to be useful for current induced magnetization switching experiments due to its softmagnetic behavior by which the critical current density can be reduced dramatically. The polycrystalline films are prepared by electron beam evaporation with varying buffer layer, cap layer, as well as Co layer thickness and number of repetitions of Co and Ni layers. Measurements of the magneto-optic Kerr effect, ferromagnetic resonance, and superconducting quantum interference device magnetometry are used to analyze the magnetic anisotropy and magnetization. Depending on the magnitude of the uniaxial anisotropy, the overall easy direction of magnetization is orientated either in plane or out of plane depending on the amplitude of the demagnetization field. Moreover, we present the results for the temperature dependence of the uniaxial anisotropy and the magnetization of the [Co/Ni] film from 5 up to 420 K, which is close to the Curie temperature. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3176901]