Method for calculating the itinerant electron entropy change from transport properties

In this work, the contribution of the free electron gas subsystem to the total entropy change during the phase transition in La(Fe,Co)$_{13-x}$Si$_{x}$ compounds has been evaluated. This estimation has been carried out using experimental data on the measurement of transport properties, in particular the Seebeck and Hall effects. In this work we have also analysed possible errors in the calculation of the carrier concentration in ferromagnets based on the results of measurements of the normal Hall coefficient. It was found that in the compounds studied it is necessary to take into account the contributions of magnetoresistance and paraprocess when calculating $R_0$.