Study of antiferro - ferromagnetic phase coexistence in Ta doped HfFe2

First order antiferromagnetic (AFM) to ferromagnetic (FM) transition in Hf1−xTaxFe2 with x~0.225 compounds was studied by resistivity, magnetization and X-ray diffraction (XRD) measurements at low temperature. Magnetization measurements as a function of temperature and magnetic field show path dependent FM phase fraction at 5 K for x=0.225. XRD measurements at 15 K show co-existing AFM and FM phases for this composition with ~0.9% unit cell volume difference of FM and AFM phase.