Magnetic, magnetocaloric, and lattice properties of the La(Fe xSi1-x)13 ferromagnets

The magnetic and lattice properties of a sample of La(Fe0.86Si0.14)(13) ferromagnet have been measured. The influence that neutron irradiation has on the physical properties of this ferromagnet is studied. It is shown that the irradiation of this sample by a fluence of 3 x 10(19) n/cm(2) increases the lattice constant a and the Curie temperature (T (C) ) as the volume magnetostriction decreases. A model of ferromagnet is proposed which satisfactorily describes the dependence a(T) of the initial and irradiated samples and their magnetic properties. The temperature dependence of the change in entropy when switching the magnetic field on and off is calculated. It is established that the change in both the magnetic and lattice parts of the total entropy at the magnetic phase transition must be taken into account for La(Fe (x) Si1 - x )(13) compounds.