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