Influence of swift heavy ion irradiation on the resistive switching behavior in epitaxial transition metal oxide based heterostructures

Abstract

Resistive Switching (RS) based memory devices are well known for a high performance computing. Herein, the RS was explored with regard to an influence of swift heavy ion irradiation (Ag15+(200 MeV)) and aging, in the SrTiO3 (STO) epitaxial heterostructure based RS devices i.e. Pt/STO/LaNiO3/LaAlO3(LAO), where Pt and LaNiO3 (LNO) act as top and bottom electrodes respectively. Prior to analyze the RS, both single (LNO/LAO) and bi-layer (STO/LNO/LAO) epitaxial heterostructures were irradiated with a three different ion doses i.e. lowest dose (1011 ions/cm2), medium dose (5×1011 ions/cm2), and highest dose (1012 ions/cm2); besides, one pristine sample of both heterostructures. Subsequently, there found strain relaxation, decrease in the interface roughness, change in the morphological roughness, and variation in the local and surface electronic structure, with an increase in the irradiation dose in the single and bi-layer heterostructures. With aging, there found behavioral change in the RS response owing to the penetration of moisture through an interfacial region between electrode (Pt) and switching layer (STO). Whereas, for the different irradiation doses, the RS at middle dose having a higher concentration of excess-Sr ([Sr]/[Sr]+[Ti]) and oxygen vacancies, showed a closed RS hysteresis loop in the negative bias region, lower set voltages, and higher endurance (up to 100 cycles); as compared, to the pristine, highest, and lowest ion-doses. This change in the RS behavior was found to be attributed due to near-surface Ruddlesden-popper (RP) type anti-phase boundaries in the STO. newline