[en] The magnetic susceptibility of (Csub(n)Hsub(2n+1)NH3)2 FeCl4, where n = 1,2,3,4 and ((CH3)2NH2)2 FeCl4, is measured in the temperature range 80 - 3000K. The results are interpreted in terms of a canted 2-dimensional antiferromagnet that approximates the X-Y model. The effect of varying the magnetic field strength on the susceptibility behaviour is discussed. (author)