EN
In this study, we have investigated the microstructure and magnetic entropy change of annealed LaFe_{11.0}Co_{0.8}(Si_{0.4}Al_{0.6})_{1.2} alloy in a form of bulk samples and melt-spun ribbons. The bulk samples were annealed at 1323 K for 20 and 49 days and the maximum values of the magnetic entropy change | ΔS_M | obtained after the change of external magnetic field from 0 to 5 T reached 7.5 J kg^{-1} K^{-1} and 7.7 J kg^{-1} K^{-1}, respectively. For the melt-spun ribbon annealed at the same temperature for 1 h, the maximum value of | ΔS_M | reaches 4.5 J kg^{-1} K^{-1}. The temperature corresponding to the maximum entropy change increased from 292 K for bulk samples to 295 K for melt-spun ribbons. The lower values of the magnetic entropy change in the melt-spun LaFe_{11.0}Co_{0.8}(Si_{0.4}Al_{0.6})_{1.2} are attributed to the presence of higher volume fraction of the secondary bcc-Fe phase in the ribbon samples.