Effects of interfacial oxygen-deficient layer on resistance switching in Cr-doped SrTiO₃ thin films

We investigated resistance switching in Cr-doped SrTiO₃ thin films with an oxygen-deficient layer at the interface. Impedance spectroscopy showed the Maxwell-Wagner relaxation due to the high-resistance oxygen-deficient layer in addition to a bulk layer of lower resistance. The high oxygen-deficient layer significantly limits the carrier injection, thus resulting in the disappearance of resistance switching. The resistance switching was recovered by reducing the oxygen vacancy concentration at the top interface by cooling or postannealing at high oxygen ambient pressures.