Defect dynamics in the resistive switching characteristics of Y0.95Sr0.05MnO3 films induced by electronic excitations

Abstract

We understand the role of defect dynamics on the resistive switching (RS) characteristics of pulsed laser deposition (PLD) grown Y0.95Sr0.05MnO3 (YSMO) manganite films on the single crystalline (100) Nb:SrTiO3 (SNTO) substrates (0.2 wt% Nb doped at Ti–site in SrTiO3). The defects were induced in the films by varying the electronic excitations through 200 MeV Ag+15 swift heavy ions (SHI) irradiation with different fluence. The θ–2θ X–ray diffraction (XRD) measurement reveals the single phasic nature of all the films. Epitaxial nature of all pristine and irradiated films has been confirmed through XRD PHI–scan (ϕ–scan) measurement. SHI fluence dependent variations in granular structure and features of the films' surface have been investigated through atomic force microscopy (AFM) measurement. Observed RS behavior has been discussed with LRS to HRS transformation, negative differential resistance (NDR) nature, backward diode character of the junctions and current compliance effect. All these features of the devices have been discussed in the context of trapping–detrapping process and formation–rupture of filamentary conducting paths in the YSMO lattices. Variation in the recorded current values has been understood in terms of alterations in the strain state between the films and substrates and surface properties of the YSMO films. Endurance behavior and retention ability (studied for 50 cycles and up to 300min time duration) of all pristine and irradiated YSMO/SNTO thin film devices suggest an effective reproducibility and reliability for their spintronic based device applications.