Investigation of the properties of Ba-substituted La_0.7Sr _0.3-x Ba_x MnO₃ perovskite manganite films for resistive switching applications

La_0.7Sr_0.3-x Ba_x MnO₃ (LSBMO: x = 0.09, 0.18, and 0.27) thin films were prepared on Pt-coated Si substrates using a radiofrequency magnetron sputtering technique at a substrate heating temperature of 450 C. The effects of varying the amount of substituted Ba ²⁺ on the physical, chemical, and electrical properties of the perovskite manganite films were systematically investigated. X-Ray diffraction showed that the growth orientation and crystallinity of films were not affected by the amount of substituted Ba cations. Raman spectroscopy was used to determine the tilt of MnO₆ octahedra and the Jahn-Teller-type distortion variation of the manganite films. The change in covalent characteristics of Mn-O bonds with increasing amounts of Ba²⁺ substituent was analyzed by x-ray photoelectron spectroscopy, specifically to examine the effects of bond characteristics on the resistive switching properties of LSBMO. The resistance of the LSBMO films increased with increasing Ba²⁺ content due to an increase in the covalent nature of Mn-O bonds. The resistive switching ratio increased with increasing Ba²⁺ amount, and relationships among resistive switching, Jahn-Teller distortion, and Mn-O bond character of LSBMO films were interpreted.