EN
In the present work the influence of Al and Ga on formation of La(Fe,Si)_{13}-type phase in magnetocaloric LaFe_{11.14}Co_{0.66}Si_{1.2-x}M_x (where x=0.1, 0.2, 0.3; M = Al, Ga) alloys subjected to annealing at 1323 K for 15 days was studied using the Mössbauer spectroscopy. For annealed samples, two crystalline phases were recognized: the dominant paramagnetic La(Fe,Si)_{13}-type phase, and minor fraction of ferromagnetic α -Fe(Co,Si). It was revealed that Al improved formation of 1:13 phase in contrast to Ga, which caused reduction of the ability of formation of the expected phase.