Author(s)

Anjali Krishnamurthy, M. P. Sharma, Bipin K. Srivastava

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Layered perovskite manganite ceramics with a nominal chemistry La_1.5Ca_1.5Mn_2-xFe_xO₇(x = 0.0, 0.05, 0.1, 0.3, 0.5) were prepared using sol-gel method. The manganese ions are highly mixed states of Mn³⁺ and Mn⁴⁺. It is found that the Mn³⁺/Mn⁴⁺ ratio decreases with the Fe doping content increasing. The conductivity and magnetoresistance (MR) were studied. The sample of x = 0.05 shows metal insulator transition (MIT) at 135 K. The MIT peak temperature (Tp) shifts towards higher temperature with increasing applied magnetic field. All the samples can be well fitted to the variable-range hopping (VRH) model. The maximum value of MR (%) [ρ(0) - ρ(H)]/ρ(0) × 100 for x = 0.05 is 34% (105 K, 7 kOe).

Layered Perovskite, M-I Transition, GMR

A. Krishnamurthy, M. Sharma and B. Srivastava, "Transport Properties of the Layer Manganite La_1.5Ca_1.5Mn_2-xFe_xO₇," World Journal of Condensed Matter Physics, Vol. 1 No. 4, 2011, pp. 153-156. doi: 10.4236/wjcmp.2011.14022.