Thermophysical and Magnetocaloric Properties of the LaFe 11.1 Mn 0.1 Co 0.7 Si 1.1 Alloy

The heat capacity ( C P ), magnetocaloric effect (∆ T and ∆ S M ), thermal diffusivity η( T ), and electrical resistivity ρ( T ) of the LaFe 11.1 Mn 0.1 Co 0.7 Si 1.1 alloy are studied in the temperature range of 80–300 K in magnetic fields of up to 8 T. Entropy change ∆ S M in a magnetic field of 1.8 T is found equal to 4.6 J/(kg K). An anomaly that consists of a sharp decrease in the electrical resistivity in a narrow temperature range and subsequent restoration of its metallic behavior is observed in the curve of temperature dependence ρ( T ) near Curie temperature T C . In the vicinity of T C , the following direct relationship between ∆ T and resistivity change ∆ρ is found in a magnetic field of 1.8 T: ∆ T ( T ) = α∆ρ( T ). The η( T ) dependence shows a pronounced minimum near T C , which indicates strong scattering of heat carriers on fluctuations of the magnetic order parameter and, possibly, on the crystal lattice distortions.