Giant Magnetoimpedance and Local Inhomogeneity in Manganite La_0.65Ba_0.35MnO₃

Abstract

The magnetoimpedance and local inhomogeneity of the manganite La_0.65Ba_0.35MnO₃ were investigated in the temperature range from 98 to 289 K. A metal – insulator transition peak occurs in the temperature dependence of impedance for the manganite La_0.65Ba_0.35MnO₃. Under application of a dc magnetic field, the metal – insulator transition temperature T_MI derived from the ac transport shifts to a higher temperature. The local inhomogeneity within the sample can be revealed through the application of ac currents with different frequencies. The ac frequency dependence of impedance for the manganite La_0.65Ba_0.35MnO₃ is found to vary with temperature. The peak value of the magnetoimpedance ΔZ⁄Z₀ can reach −26.3% at 100 kHz under a field H=3.98×10⁵ A/m. The impedance of the manganites can be influenced by magnetic fields through permeability and resistivity.