Solid State Science and Technology, Vol. 15, No 1 (2007) 203-209

ISSN 0128-7389



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.



[1] Pal, S., Banerjee, A., Rozenberg, E. and Chaudhuri, B.K. (2001); Polaron hopping

conduction and thermoelectric power in LaMnO3+ , Volume 89, Issue 9, pp.


[2] Zener, C. (1951); Phys. Rev. 81, 440; P. de Gennes, Phys. Rev., 118, 141.

[3] Banarjee, A., Pal, S., Rozenberg, E., Chaudhuri, B.K. (2001); Magnetoresistance

and magnetothermoelectric power of La0.5Pb0.5Mn1-xCrxO3. J. Chem. Phys., 115,


[4] Sayani Bhattacharya, Sudipta Pal, Mukherjee, R.K., Chaudri, B.K., Neeleshwar,

S., Chen, Y.Y., Mollah, S. and Yang, H.D. (2004); Journal of Magnetism and

Magnetic Materials, 269, 359 – 371.

[5] Saket Asthana, Bahadur, D., Nigam, A.K. and Malik, S.K. (2004); J/ Phys:

Condens. Matter, 16, 5297 – 5307