Magnetic field modulated dielectric relaxation behavior of Pt/BiScO 3-PbTiO 3/La 0.7Sr 0.3MnO 3 heterostructure in metal-insulator transition region: An equivalent-circuit method

Abstract

Utilizing temperature and magnetic field dependent dielectric spectroscopy, two different dielectric relaxation processes, both accompanied with prominent positive magnetodielectric (MD) effects, were observed in Pt/BiScO 3-PbTiO 3/La 0.7Sr 0.3MnO 3 (Pt/BSPT/LSMO) heterostructure. An equivalent circuit model is established to quantitatively describe the relaxation data well. The simulation results elucidated that one relaxation process can be attributed to magnetic order associated BSPT/LSMO interfacial relaxation with abnormal dynamics feature. Another one is due to the external contact interface contributions. Both relaxation dynamics can be tuned, via magnetic field controlled localization of free interfacial charges, to induce MD effects in BSPT/LSMO interfaces and nonmagnetic Pt/BSPT contacts. © 2011 American Institute of Physics.