Thin Solid Films, Vol.685, 151-160, 2019
Resistive switching effect and charge conduction mechanisms in Y-0.95 Sr-0.05 MnO3 manganites: Dynamic role of defects
The dynamic role of defects introduced through swift heavy ion (SHI) irradiation on structural, resistive switching (RS) behavior and charge conduction mechanisms of Y-0.95 Sr-0.05 MnO3 (YSMO) manganite films are reported in the present communication. YSMO films were grown on single crystalline (100) n-type semi-conducting Nb: SrTiO3 (SNTO) substrates using pulsed laser deposition technique. All the films were irradiated by 200 MeV Ag+15 ions with different fluence to understand the effect of irradiation on the RS behavior of YSMO/SNTO films. In order to study the structural properties, theta-2 theta X-ray diffraction measurement was performed at room temperature. To understand the RS behavior of presently studied YSMO/SNTO pristine and irradiated films, hysteretic current-voltage (I-V) characteristics were performed under the sweeping bias voltage cycles: 0 V -> + 10 V -> 0 V -> -10 V -> 0 V across YSMO/SNTO interface at room temperature. In the present case, I-V curves show the p-n junction/diode like asymmetric behavior along with two different resistive states under both the positive and negative bias modes. Observed RS behavior has been attributed to the trapping-detrapping processes, modifications in the depletion region and movement of oxygen vacancies across the interface barrier between the YSMO films and SNTO substrates. Our main aim is to understand an active role of defects, strain modifications and local annealing or recrystallization effect across YSMO/SNTO interfaces under the effect of SHI irradiation for the modifications in the RS behavior. Thermionic emission mechanism has been identified to fit the different cycles of RS behavior of YSMO/SNTO pristine and all irradiated films to understand possible charge conduction processes across their interfaces. Time scale stability has been investigated for presently studied YSMO/SNTO films which suggest the improved memory abilities of the films irradiated with higher ion fluence.