New measurements of high field magnetisation ( I s ), remanence ( I s ), and coercive force ( H c ) are presented between 4 and 300 K for x = 0.4, 0.5, 0.6 and 0.8 (Fe 3− x Ti x O 4). For x = 0.4 a pronounced minimum is found at T⋍100 K and for x = 0.5 and 0.6 broad minima occur around T⋍200 K , apparently coinciding with the temperature for K 1⋍0 . The magnetic properties below T⋍60 K ar complex and were found to be significantly changed by cooling in the presence of a high magnetic field. With no applied field during cooling, a distinct decrease in I s is observed for T⪅60 K, at which temperature there is a peak in the value of I rs . The effe cooling is to eliminate the sharp decrease in I s , reduce H c and to increase I rs below ∼60 K to a value the peak value, giving essentially a square hysteresis loop. The results are interpreted in terms of a form of crystallographic phase transition coupled to the magnetisation direction, possibly by the magnetostriction. Square hysteresis loops in ferrites have been explained by the presence of Jahn-Teller ions and, in the present case, the low temperature of the observed effect may be a consequence of the weak Fe 2+ Jahn-Teller ion coupled to other effects such as spin-lattice coupling. Details of this work can be found in Schmidbauer, E. and Readman, P.W., 1982. Low temperature magnetic properties of Ti-rich FeTi spinels. J. Magn. Magn. Mat., 27: 114–118. A paper reporting further work on Fe 2.4Ti 0.6O 0.4 is in preparation.