Insights into the coexistence of tunneling, hopping and jump models controlling the conduction phenomenon in doped lanthanum manganite compound

Abstract

The present investigation provides different possible reasons to explain the change of the conduction process in the studied material. Doped lanthanum manganite compound was successfully prepared using the conventional solid-state method. XRD patterns are used to confirm the formation of the desired manganite compound. Under both of the temperature and frequency effects, the charge dynamics are deeply investigated. The conductivity spectra obey to double Jonscher power law (DJPL), single Jonscher power law (JPL) and the classical Drude model. Successful and unsuccessful jumps describe the AC-conductivity regime in the dispersive frequency region. In the intermediate frequencies, the transport properties are explained by classical hopping (CBH) and tunneling (NSPT) models. The low-frequency range is associated to the DC-conductivity regime. The latter shows the possibility of contribution of three hopping models in the transport properties. The change in such conduction model is synchronized with ANC temperature that describes the temperature at which the trapped centers are vanished. Such observations prove the possibility of the presence of multi-trapped centers. Shimakawa model, that assumes the presence of multi-phonons, was equally used to understand the charge carriers dynamics in the intermediate temperatures. The matching between complex impedance and conductivity analyses confirms the presence of relaxation process which is related to charge carries hopping.