Solid State Science and Technology, Vol. 15, No 1 (2007) 203-209
HOPPING CONDUCTION IN La1/2Ba1/2(Mn1-xAlx)O3
Huda Abdullaha, Abdul Halim Shaaria and Hasan Abu Kassimb
aDepartment of Physics, Faculty of Science,
Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia
bDepartment of Physics, Faculty of Science,
Universiti Malaya, 40603 Kuala Lumpur, Malaysia
Electrical resistivity behaviour of La1/2Ba1/2(Mn1-xAlx)O3 compounds, prepared by the solid state reaction, have been investigated below the charge-ordering temperature to understand the mechanism of conduction. On analyzing the data by using several theoretical models, it is found that the metallic (ferromagnetic) part of the resistivity ( ρ ) (below TP) fits well with the equation ρ = ρ0 + ρ2T2, where ρ0 is due to the importance of grain/domain boundary effects, a second term ~ρ2T2 appears that might be attributed to the electron–electron scattering. In high temperature (Tp<T<θD/2) paramagnetic insulating regime, the resistivity of samples obey the T-1/4 law, characteristic of variable range hopping (VRH) model.
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