Direct measurement of the magnetocaloric effect on LaFe13−x−yCoySix compounds near room temperature

International audienceThe magnetic and magnetocaloric properties of LaFe11.9−yCoySi1.1 compounds with y = 0.8 and 0.9 have been investigated. The temperature dependence of magnetization data revealed that LaFe11.1Co0.8Si1.1 and LaFe11Co0.9Si1.1 exhibit a second-order magnetic transition near room temperature at 282 and 294 K, respectively. Under a magnetic field change of 5 T, the maximum values of isothermal entropy change −ΔS are found to be 15 and 13.5 J/kg K for y = 0.8 and 0.9, respectively. The refrigerant capacity has been calculated to be 320 J/kg for y = 0.8 and 266 J/kg for y = 0.9 under a field change of 5 T. Direct measurements of the temperature change for LaFe11.9−yCoySi1.1 compounds around room temperature were also performed. Measurements of ΔT were performed in adiabatic conditions with practice-oriented method by using a specially developed test bench. For both materials, the normalized temperature change was found to be about 1 K/T at their Curie temperatures