EFFECT OF THE PRESSURE AND THE RARE-EARTH SUBSTITUTION ON THE VERWEY TRANSITION OF YFE2O4

Effects of the hydrostatic pressure as well as the rare earth substitution are examined on the two-step Verwey transition of the stoichiometric YFe2O4, by the electric and the magnetic measurements. The upper and the lower transition temperatures decrease with the compression by 2.6 and 10.5 K/kb, respectively. Substitution of Y by Lu decreases whereas that by Dy increases the transition temperature. At room temperature in the high conductivity phase, lattice constants in the hexagonal frame, a and c, are measured for substituted crystals and for the stoichiometric YFe2O4 under pressure. It is shown that the upper and the lower transition temperatures are independent from c but decrease 10 and 42 K, respectively, by 10-3 compression of the lattice along the a axis. The character of the transition is discussed briefly. © 1990, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.