Comparison of the Giant Magnetoimpedance Effect between Ferromagnetic La_0.64Ba_0.36MnO_3-δ and Paramagnetic La_0.64Ba_0.36Mn_0.95Fe_0.05O_3-δ

Abstract

In the present paper, ac electric transport behavior of La_0.64Ba_0.36Mn_1−xFe_xO_3−δ with x=0 (the ferromagnetic phase) and x=0.05 (the paramagnetic phase) are comparatively investigated at a temperature of 300 K . The reactance X is positive for the x=0 but negative for the x=0.05. For x=0, the impedance Z increases at first, undergoes a peak and a valley, and finally increases again with increasing ac frequency. On the contrary, for x=0.05, the impedance decreases monotonically with increasing ac frequency. Meanwhile, the giant magnetoimpedance effect has been found in both ferromagnetic x=0 and paramagnetic x=0.05 at 300 K . Results also show that with increasing frequency the change ratio of the magnetoimpedance (Z(0)–Z(5172 A·m⁻¹))⁄Z(0) increases for the sample x=0 but decreases for the sample x=0.05.