Kinetics of thermally induced first-order magnetic transition in La(Fe0.88Si0.12)13 itinerant electron metamagnet

A nucleation-growth phenomenon has been investigated in the thermally induced first-order transition between the ferromagnetic and paramagnetic states of La(Fe0.88Si0.12)13 itinerant-electron metamagnetic (IEM) compound by measuring the AC susceptibility. Temperature dependence of the transition rate upon cooling exhibits a Johnson–Mehl–Avrami type variation and the Avrami exponent is determined to be 2.2. The thermal variation of the transition rate is scaled by the cooling rate, indicating that generation and dissipation of the latent heat are important for the kinetics of the growth process of the thermally induced transition.

► Kinetics of the thermally induced first-order phase transition between the ferromagnetic and paramagnetic phases is proved in La(Fe0.88Si0.12)13.
► Growth rate of the ferromagnetic region is represented by the Johnson–Mehl–Avrami model with the Avrami exponent of ∼2.2.
► The influence of the local elastic energy is relatively small in comparison with the magnetostructural transition and release of the latent heat dominates the kinetics in the magnetic transition of La(Fe0.88Si0.12)13.