We have developed a procedure for x-ray fluorescence determination of the constituent composition and thickness of two-layer Ni-Fe-Mn/Cr films deposited on Polikor, an aluminum oxide ceramic. We have calculated correction coefficients taking into account interelement interference effects in this system. We have experimentally determined the density of the materials making up the composition of the films. We have established and present the metrological characteristics of the procedure developed.Keywords: x-ray fluorescence method, two-layer thin film, film composition and thickness, interelement interference effects.Introduction. Application of magnetic film elements is one of the most promising directions for development of discrete data storage devices. Analysis of experimental data suggests that it is expedient to use systems based on iron and nickel with addition of dopants in the form of cobalt, manganese, molybdenum, chromium, and phosphorus to make magnetic films. Development of the technology for production of thin films with specified properties requires constant monitoring in each stage of their fabrication.Earlier we presented procedures for determining the composition and thickness of thin monolayer multicomponent [1, 2] and two-layer films, both single-component [3,4] and composites where one layer is single-component and the second layer is two-component [5,6]. This paper is devoted to development of a procedure for determining the composition and thickness of films of the Ni-Fe-Mn/Cr system, the top layer of which is three-component.Experimental Section. Study and development of procedures for x-ray fluorescence analysis of both the end product (two-layer Ni-Fe-Mn/Cr thin films on Polikor substrates) and the starting materials (bulk samples of Ni-FeMn alloys) were carried out on a VRA-20R x-ray fluorescence spectrometer (Carl Zeiss Jena, Germany). The optimal conditions for analysis of the studied systems are given in Table 1.The reference samples in analysis of the composition of the target were (Table 2): a kit of 96 reference samples [8], bulk samples of 47NKhR, 50NP, 79NM, and thick Ni-Fe-Mn films, the composition of which were determined by atomic absorption (AA) on a Perkin-Elmer 603 spectrometer. The 50NP and 79NM samples contained small amounts of carbon, aluminum, silicon, sulfur, and phosphorus. The samples were disks of diameter 22 mm.The electrolytically obtained thick (>200 μm) films were subsequently used as targets for sputter deposition of the thin films on 24 × 30 mm Polikor. In order to obtain the thin films, we used ion plasma sputtering under vacuum on a URM-3.279.026 apparatus. The starting materials for sputtering single-component thin films, subsequently used as reference samples, and bulk samples in determining the relative intensities I A 0 ⁄ I A ∞ were elemental metals at