Chemical order and crystallographic texture of FePd:Cu thin alloy films

摘要

FePd thin films have been recently considered as promising material forhigh-density magnetic storage devices. However, it is necessary to find aproper method of fabrication for the (001)-textured and chemically well-orderedalloy. In this paper, we present the detailed investigations of latticeparameters, chemical order degree, grain sizes and crystallographic texture,carried out on FePd alloys with 10 at.% of Cu addition. The initial [Cu(0.2nm)/Fe(0.9 nm)/Pd(1.1 nm)]x5 multilayers were thermally evaporated in anultra-high vacuum on MgO(100), Si(100), Si(111) and Si(100) covered by 100 nmthick layer of amorphous SiO2. In order to obtain homogeneous FePd:Cu alloy,the multilayers were annealed in two different ways. First, the samples wererapidly annealed in nitrogen atmosphere at 600oC for 90 seconds. Next, the longannealing in a high vacuum for 1 hour at 700oC was done. This paper focuses onquantitative investigations of the chemical order degree and crystallographictexture of ternary FePd:Cu alloys deposited on four different substrates. Inorder to obtain both quantities we have taken a novel approach to consider theproblem of dopant atoms located in the FePd structure. The studies of thestructure were done using X-Ray Diffraction (XRD) performed with synchrotronradiation and pole figures measurements. We have found that the addition of Cuchanges the FePd lattice parameters and lattice distortion. We have also shown,that using different substrates it is possible to obtain a FePd:Cu alloy withdifferent chemical order and texture. Moreover, it was observed that texturecategory is substrate dependent.