Effect of the Frequency of a Cyclic Magnetic Field on the Adiabatic Temperature Change in Manganite Pr0.7Sr0.2Ca0.1MnO3

The effect of microstructure and the frequency of change in an alternating magnetic field on the adiabatic temperature change ΔTad in manganite Pr0.7Sr0.2Ca0.1MnO3 has been studied. It has been shown that the transformation of specimens from a denser to looser microstructure leads to both a decrease in ΔTad and a stronger frequency dependence of the adiabatic temperature change. For the specimen with an annealing temperature of 1300°C, ΔTad is 0.6 K at a frequency of 1 Hz in a field of 1.2 T to decrease to 0.3 K at 20 Hz (by more than 50%). For the specimen with an annealing temperature of 600°C, ΔTad is 0.45 and 0.06 K at frequencies of 1 and 20 Hz, respectively (i.e., decreases by more than 80%).