A series of ferromagnetic [A(x)B(60-x))(2) multilayers, where A=Fe15N85, B=Fe25Ni75, and x is the thickness of layer A in nanometer, were manufactured by the vapor evaporation method. Three measurements were carried out on each sample: the Auger depth-profile analysis, a measurement of Young's modulus E-f by the nano-indentation system, and the measurement of saturation magnetostriction lambda(s) by the optical-cantilever system. Bulk and thin-film samples have different Young's modulus, and, moreover, in the multilayer, the modulus E-f becomes a nonlinear function of x. A set of lambda(s) data derived using the measured E-f is compared with data based on the bulk value E-t=2.0x10(11) N/m(2). The deposition temperature here is T-s=200 degreesC. With increasing T, (here up to 400 degreesC), the interfacial mixing increases as well. The deviation Deltalambda(s) of magnetostriction from theoretically predicted linear behavior is found to be oscillatory at low T-s (where Deltalambda(s) changes signs), but monotonic at high T-s (where Deltalambda(s) maintains the same sign). A qualitative explanation of these phenomena is provided. (C) 2004 Elsevier B.V. All rights reserved.