Papers by Keyword: LSMO

Abstract: Mixed valence manganite materials have been studied due to their interesting physical properties such as their magnetoresistance (MR) effect. The change of Mn³⁺/Mn⁴⁺ ratio affects the possible bonds between anion and cation and their spin structure that may occur in the samples. The aim of this research is to study the change of magnetoresistance effect and magnetic properties of La_0.67Sr_0.33MnO₃ (LSMO) by doping the Mn site with Ni ion. La_0.67Sr_0.33Mn_1-xNi_xO₃ samples were synthesized by using sol-gel method and characterized by using X-ray diffractometer (XRD) and Energy Dispersive X-ray spectroscopy (EDX) to confirm whether Ni has been doped successfully to the parental compound or not. XRD results showed that the samples have a single phase and Ni peak has been detected in the EDX result of Ni-doped LSMO. Resistivity and magnetic measurement showed that LSMO material has ferromagnetic metallic behavior, while x = 0.20 Ni-doped LSMO sample showed paramagnetic insulator behavior. The absolute value of the MR for un-doped sample is higher than the doped sample when the low field is applied, while under the influence of the high magnetic field, it become smaller than the doped sample.

Abstract: La_0.67Sr_0.33MnO₃ (LSMO)/Pb_0.92La_0.08Zr_0.65Ti_0.35O₃ (PLZT) composite film was fabricated on a (001) LaAlO₃ (LAO) single crystal substrate by a sol-gel technique. The results from X-ray diffraction (XRD) indicated that LSMO and PLZT could grow successively on LAO substrate with (001) preferred orientation. The ferroelectric and ferromagnetic properties of LAO/LSMO/PLZT composite film were also investigated. The results showed that the remnant polarization P_r, and coercive field E_c of the composite film at room temperature were 36.38 μC/cm² and 512.43 kV/cm respectively. Moreover, the composite film exhibited significant ferromagnetic hysteresis loops and soft magnetic behavior at temperatures lower than 250 K.

Abstract: Resistive random access memory (ReRAM) is a promising candidate for next generation nonvolatile memory. La_0.7Sr_0.3.MnO₃ (LSMO) of perovskite manganite family has a great deal of attention for ReRAM material because it makes resistive switching (RS) of interface type without a “forming process”. However, the full understanding of the electronic structure and RS mechanism of LSMO remains a challenging problem. Therefore, this study performed spectromicroscopic analysis to understand the relation between the change of electronic structure and RS characteristic. The results demonstrated the electron occupation by field-induced oxygen vacancies and strong correlation effects.

Abstract: La_1-xSr_xMnO₃ (LSMO) (x=0.1, 0.2, 0.3, 0.4)powders were synthesized by high temperature solid phase method, and the crystal structure and morphology were characterized by XRD and SEM. Results indicated that the pure perovskite type LSMO could be obtained after sintered at the temperature of 1000°C for 6h. The average particle size of the powders decreases with the increasing concentration of Strontium.

Abstract: The La1-xAxMnO3 (A=Sr, Ca, Ba) film was prepared by excimaer laser-assisted metal organic deposition (ELAMOD). To understand the important controlling factor of the epitaxial growth using ELAMOD, the effects of the substrate temperature, substrate type, wavelength, and film thickness on the epitaxial growth were investigated. When the film thickness was 200nm with heating at 250°C, a polycrystalline LSMO film was formed on the LAO substrate. On the other hand, at 80nm, an epitaxial LSMO film was formed on the LAO substrate at 500°C. The epitaxial growth of the LSMO film was found to be dependent on the substrate materials and the laser wavelength. The formation of the epitaxial and polycrystalline LSMO films was discussed