Structural, Magnetic and Magnetotransport Properties of Sol-Gel Synthesized La_0.67Ca_0.33MnO₃:TiO₂ Nanocomposite

Abstract

Colossal magnetoresistive (CMR) materials have been widely studied because of their huge potential in spintronic technology. An introduction of secondary phase to the manganite matrix is able to improve the low field magnetoresistance (LFMR). This method is favoured by recent research works as it requires a lower magnetic field compared to intrinsic magnetoresistance. Structural, magnetic properties and magnetotransport properties of polycrystalline (1-x) La0.67Ca0.33MnO3 (LCMO): x TiO2 composites where x = 0.00, 0.05, 0.10, 0.15 and 0.20 were investigated in this work. Polycrystalline La0.67Ca0.33MnO3 (LCMO) was synthesized via sol-gel method and pre-sintered at 800 °C before appending with nano-sized TiO2. All samples are in LCMO phase having an orthorhombic structure with space group Pnma. The crystal structural parameter is studied by using Rietveld refinement. As TiO2 content increases, the magnetization is getting higher as observed via vibrating sample magnetometer (VSM) analysis at room temperature. Magnetotransport properties of the pure LCMO sample have been studied from 80 – 220 K. The LFMR is enhanced as the temperature drops. The results have shown LCMO: TiO2 manganite composite is an excellent candidate for future magnetic sensors and memory devices.

Regulating the Electron Transport Mechanism and Increasing Magnetoresistance: The Role of CuO Filler in La0.7Sr0.2Ca0.1MnO3 Grain Boundary

“…[7]- [15]. The CMR effect is of great importance in both fundamental sciences and its advanced applications, such as magneto-resistive transducers and sensors, which have garnered increasing attention [16]- [18].…”

“…The addition of a secondary phase has the potential to improve the grain boundary effect in perovskite manganates [21]- [23]. Researchers have studied a range of composite perovskite manganite materials, including those incorporating Ag [24], NiO [25], ZnO [26], CuO [2], TiO2 [27], MgO [20], Ta2O5 [28].…”

Microstructure, Magnetic and Electrical Transport Properties of Sol-Gel Synthesized La_0.7Sr_0.2Ca_0.1MnO₃:TiO₂ Composite

“…In expansion to a crucial understanding of the instrument of the CMR impact, studies have moreover been persuaded by the potential applications of these materials. In any case, an intrinsic CMR effect on perovskite manganese, caused by a double exchange mechanism [9][2], was found over a magnetic field scale of a few Tesla and a narrow temperature range [10]. Recently, grain boundary effect in perovskite manganese have been considered intensively [11], as a found by Xiong et al, [12] the presence of grain boundaries in polycrystalline samples cause a huge low field magnetoresistance (LFMR) effect over a wide temperature range underneath the Curie Tc temperature.…”