Metamagnetic transition and the anomalous virgin magnetization curve inCe(Fe0.96Ru0.04)2

Abstract

We present results of dc magnetization measurements investigating the magnetic field-induced metamagnetictransition in Ce(Fe0.96Ru0.04)2. In the temperature region where this material undergoes a ferromagnetic toantiferromagnetic first-order phase transition, the isothermal virgin magnetizationcurve lies distinctly outside the envelope magnetization curve obtained in thesubsequent field cycles. We show that this anomalous behaviour of the virginmagnetization curve arises due to the dependence of the initial zero field magnetic stateon the temperature–field history of the sample in the concerned temperatureregime. This origin of the anomalous virgin magnetization curve is distinctlydifferent from the very similar behaviour observed earlier in Al- and Os-dopedCeFe2 alloys, where this feature was associated with the kinetic arrest of the first-orderferromagnetic to antiferromagnetic transition.