First-order transition from ferromagnetism to antiferromagnetism in Ce(Fe_0.96Al_0.04)₂: A magnetotransport study

Magnetotransport behavior is investigated in detail across a first-order magnetic phase transition from a ferromagnetic state to an antiferromagnetic state in a polycrystalline Ce(Fe_0.96Al_0.04)₂ sample. The study clearly brings out various generic features associated with a first-order transition, viz., hysteresis, phase coexistence, supercooling and superheating, and the presence and limits of the metastable regimes. These magnetotransport study results exhibit and support all the interesting thermomagnetic history effects that were observed in our earlier dc magnetization study on the same sample. Most notable here is the initial (or virgin) resistivity vs field curve lying outside the hysteretic “butterfly-shaped” magnetoresistivity loops obtained on cycling the magnetic field between high enough positive and negative strengths. These findings, bearing a one-to-one similarity with the data obtained in their magnetic counterpart (i.e., dc magnetization), are ascribed an origin due to the arresting of this first-order transition kinetics at low temperature and high magnetic field.