Effect of TiO2 addition on the structure, magnetic, electrical, and magneto-transport properties of La0.67Ca0.33MnO3 (LCMO) system

Jamaluddin, Norsyazwani (2022) Effect of TiO2 addition on the structure, magnetic, electrical, and magneto-transport properties of La0.67Ca0.33MnO3 (LCMO) system. [Project Paper] (Submitted)

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Abstract

Numerous studies have been conducted to enhance the extrinsic magnetoresistance (MR) effect by addition of an oxide compound as an artificial layer. Since the discovery of ferromagnetic LaMnO3 in 1950, colossal magnetoresistance (CMR) materials, specifically perovskite manganites, have been extensively studied. The primary objective of this research is to determine the effect of varying the TiO2 content in LCMO. In this research pure La0.67Ca0.33MnO3 (LCMO) and LCMO with addition of various concentrations of Titanium Oxide (TiO2), including 0.5 %, 1%, 3%, and 5% has been prepared by using the sol-gel technique. Five characterization techniques were utilized to determine the material's structural, magnetic, and electrical properties: thermogravimetric analysis (TGA), X-ray diffraction (XRD), alternating current susceptibility (ACS), vibrating sample magnetometer (VSM), and Hall effect Measurement System (HMS). The TGA revealed a two-step process, with the first stage indicating removal of water crystal content and continuously significant decomposition of precursor impurities, and the last step indicating the formation of a LCMO phase where reaction between the oxide and vaporized oxygen occurred. The XRD analysis revealed that the varied compositions of TiO2 added to LCMO had no effect on the LCMO's real structure. The magnetization versus magnetic field graph shows that all samples behaved as paramagnetic at room temperature, with the magnetization decreasing as the secondary phase content increased. Increasing the amount of TiO2 used results in a steady reduction in magnetization and Curie temperature while the resistivity rises significantly. Extrinsic CMR, also known as low field magnetoresistance (LFMR), is achieved by spin polarised tunnelling between grain boundary interfaces in a manganite composite. The composition of TiO2 increases LFMR and lowers metal-insulator transition (TMI). The TMI value shifts to the lower temperature from pure to the highest concentration of LCMO/TiO2 due to the double exchange (DE) impact is being decreased, making Jahn-Teller (JT) distortion more favourable after TMI value. The intrinsic MR weakened as TiO2 was added to the LCMO system.

Item Type:	Project Paper
Faculty:	Fakulti Sains
Depositing User:	Ms. ROHANA ALIAS
Date Deposited:	05 Jun 2024 04:09
Last Modified:	05 Jun 2024 04:09
URI:	http://psaspb.upm.edu.my/id/eprint/1892

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