Abstract X-ray and detailed 119 Sn Mössbauer studies have been performed on the title compounds. The accurate lattice parameters were determined. The temperature evolution of magnetically split spectra allows for estimation of the respective transition temperatures. The recorded spectra below and around T N can only be fitted as a superposition of magnetically split and unsplit components and the fraction of the latter decreases with temperature. The possible alignment of the magnetic Sm moments is proposed.