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Magneto-transport studies on La2/3Ba1/3(Mn1–x Alx)O3 for low field sensing applications


Abdullah, Huda and Shaari, Abdul Halim and Lim, Kean Pah and Azman, Nur Jannah (2009) Magneto-transport studies on La2/3Ba1/3(Mn1–x Alx)O3 for low field sensing applications. Materials Research Innovations, 13 (3). pp. 386-390. ISSN 1432-8917; ESSN: 1433-075X


The magnetic and transport properties of La2/3Ba1/3(Mn1−x Al x )O3 (x=0·0, 0·1, 0·2, 0·3 and 0·4) compounds, prepared by the solid state reaction, have been investigated. Samples show a metal–insulator transition excluding the sample x=0·0. With increased Al doping, the metal–insulator transition temperature T p is shifted to lower temperatures. Grain size reduction leads to a larger resistivity and a decrease in T p. Upon analysing the data using several theoretical models, it was found that the metallic (ferromagnetic) part of the resistivity ρ (below T P) fits well with the equation ρ=ρ 0+ρ 2 T2, where ρ 0 is due to the importance of grain/domain boundary effects, and a second term ρ 2 T2 might be attributed to the electron–electron scattering. The microstructure results indicate that the porosity of the samples increased when the concentration increased. The magnetoresistance (MR) is defined as %MR=100×[ρ(H,T)–ρ(0,T)]/[ρ(0,T)], where ρ(H,T) and ρ(0,T) are the resistivities at temperature T, with an applied magnetic field H and zero applied magnetic field respectively. All samples show low-field magnetoresistance and high-field magnetoresistance regions. The highest percentage of LFMR at a temperature of 100 K is ∼210% MR/Tesla, measured for the sample x=0·2. For x=0·3, the sample reveals the highest colossal magnetoresistance value among other doped compounds with 27·27% at 100 K.

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Additional Metadata

Item Type: Article
Divisions: Faculty of Science and Environmental Studies
DOI Number: https://doi.org/10.1179/143307509X441630
Publisher: W. S. Maney & Son
Keywords: Metal–insulator transition temperature Tp; Resistivity; Low-field magnetoresistance
Depositing User: Nabilah Mustapa
Date Deposited: 04 Oct 2019 08:26
Last Modified: 04 Oct 2019 08:26
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.1179/143307509X441630
URI: http://psasir.upm.edu.my/id/eprint/15506
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