We report the results of the inhomogeneous broadening and high temperature hole burning in M(y)M'1-yFCl0.5Br0.5:Sm2+ system (M, M'=Ca, Sr, Ba; y=0-1). The influence of Sm3+ as electron trap on hole burning is discussed and new trap is introduced in Yb-doped SrFCl:Sm2+ crystals.