Fe83Ga17Prx alloys,where x ＝ 0,0.2,0.4,0.6 and 1.0,were prepared by a non-consumable vacuum arc melting technique under an inert argon gas atmosphere.The crystal structure and surface morphologies of the alloys were studied by X-ray diffraction(XRD)and scanning electron microscopy(SEM),respec-tively.Local compositional variations were measured by energy dispersive X-ray spectroscopy(EDXS).The magnetostriction coefficients of the alloys were measured by means of a differential resistive strain sensor.The magnetism of the sample was measured by a vibrating sample magnetometer(VSM).The results show that the parent Fe83Ga17 alloy consists of a single A2 phase of bcc symmetry,whereas the Pr doped Fe83Ga17 alloys are composed of the A2 phase of bcc structure and a small volume fraction of PrGa2 as a secondary phase.Most importantly,with increasing x,the magnetostriction coefficient of the Fe83Ga17Prx alloys first increases reaching a maximum saturation magnetostriction coefficient of 192 ppm for x＝0.6 at a magnetic field strength of 486 kA/m,then decreased.This maximum represents a 400％increase over the parent alloy with a mere 0.6 at％Pr doping.