EFFECT OF LOW-LEVEL TITANIUM(IV) DOPING ON THE RESISTIVITY OF MAGNETITE NEAR THE VERWEY TRANSITION

The effects of Ti substitution for Fe on octahedral sites in magnetic has been investigated through electrical resistivity measurements. In a manner analogous to zinc ferrites, the Verwey transition temperature is depressed with increasing Ti content. The Verwey transition is of first order in Fe3-yTiyO4 in the concentration range 0 less-than-or-equal-to y less-than-or-equal-to y(c) = 0.012; for y(c) less-than-or-equal-to y less-than-or-equal-to 3y(c) the transition is of second order, and for y > 3y(c) the phase transformation is completely eliminated. The data are correlated with comparable work on dilute zinc ferrites and nonstoichiometric magnetite, and the implications of the findings are discussed.