Specific Features in the Field and Temperature Dependences of the Magnetostriction of Multicomponent Sm $${}_{\mathbf{0.2}}$$ (Y,Tb) $${}_{\mathbf{0.8}}$$ Fe $${}_{\mathbf{2}}$$ Alloys

This paper presents results on the synthesis of multicomponent $$\textrm{Sm}_{0.2}(\textrm{Y},\textrm{Tb})_{0.8}\textrm{Fe}_{2}$$ alloys and the study of their magnetostriction properties. In this system, it is possible to control competing exchange interactions by varying the concentrations of components, the temperature, and the external magnetic field and to observe a variety of unique phenomena, such as magnetization and magnetostriction compensation. Using X-ray diffraction analysis, it has been established that these alloys have a cubic crystal structure of the C15 Laves phase. Longitudinal and transversal magnetostrictions were studied within a temperature range from 80 to 300 K in magnetic fields of up to 12 kOe. The bulk and anisotropic magnetostrictions were calculated from experimental values. The sign inversion of bulk magnetostriction in Sm $${}_{0.2}$$ Y $${}_{0.8}$$ Fe $${}_{2}$$ was revealed at $$T=150$$ K. It has been shown that the bulk magnetostriction of some studied alloys is almost invariable and close to zero within a broad temperature range of 150–300 K. The results are discussed within the model of a three-sublattice magnet with competing exchange interactions.