Itinerant-electron metamagnetism of the Hf1−xTaxFe2 (x=0.125 and 0.14) compounds under high pressure

The effect of hydrostatic pressure on the magnetic properties has been investigated for itinerant-electron metamagnetic Hf1−xTaxFe2 (x=0.125 and 0.14) compounds which exhibit a temperature-induced transition from the ferromagnetic (FM) to the antiferromagnetic (AFM) state upon heating. Both the magnetic transition temperature TFM-AFM and the spontaneous magnetization MS decreases with increasing pressure. The application of an external pressure leads also to the strong increase of the AFM-FM transition field μ0Hcr. The magnitude of the pressure coefficient, dln(TFM-AFM)/dP, is much larger than that of dln(MS)/dP. This extremely large difference between the pressure coefficients is explained by the influence of spin fluctuations on the magnetovolume effects in the compounds Hf0.875Ta0.125Fe2 and Hf0.86Ta0.14Fe2.