Ohmic contacts and n-type doping on TixCr2 − xO3 films and the temperature dependence of their transport properties

A procedure to dope n-type Cr2 − xTixO3 thin films is proposed. Besides doping the material, at the same time the method forms ohmic contacts on TixCr2 − xO3 films. It consists on the deposition of 10 nm Ti and 50 nm Au, followed by thermal annealing at 1000 °C for 20 min in N2 atmosphere. Ohmic contacts were formed on three samples with different composition: x = 0.17, 0.41 and 1.07 in a van der Pauw geometry for Hall effect measurements. These measurements are done between 35 K and 373 K. All samples showed n-type nature, with a charge carrier density (n) on the order of 1020 cm− 3, decreasing as x increased. As a function of temperature, n shows a minimum around 150 K, while the mobilities have an almost constant value of 11, 28 and 7 cm2V− 1 s− 1 for x = 0.17, 0.41 and 1.07, respectively.