Recrystallization of glass: homogeneous vs. heterogeneous nucleation in La(0.5)Ca(0.5)MnO3

We probe through magnetization and resistivity measurements a kinetically arrested glass-like but long-range ordered magnetic state. The transformation kinetics of the magnetic field-temperature induced broad first-order transition from ferromagnetic-metallic (FMM) to antiferromagnetic-insulating (AFI) state gets hindered at low temperature in a La(0.5)Ca(0.5)MnO3 sample. A fraction of high-temperature FMM phase persists to the lowest temperature, albeit as a non-ergodic state. We present a phenomenology for this glass-like but long-range order FMM phase which devitrifies on heating and converts to equilibrium AFI phase. The residual kinetically arrested FMM phase can be recrystallized' to AFI state by annealing and more efficiently by successive annealing, presumably by heterogeneous nucleation. This glass-like state shows a stimulating feature that when the fraction of glass is larger the recrystallization’ is easier.