Joule self-heating effects and controlling oxygen vacancy in La0.8Ba0.2MnO3 ultrathin films with nano-sized labyrinth morphology

Guankai Lin,Hong Zhu,Haoru Wang,Wei Tong,Xuhui Cai

doi:10.1063/5.0009801

Abstract

Electric current induced Joule heating effects have been investigated in La0.8Ba0.2MnO3 ultrathin films deposited on a LaAlO3(001) single crystal substrate with a smaller lattice constant by using the sol–gel method. By applying moderate bias currents (∼10 mA), it is found that Joule self-heating simply gives rise to a temperature deviation between the thermostat and the test sample, but the intrinsic ρ(T) relationship measured at a low current (0.1 mA) changes a little. However, it is noteworthy that the low-temperature transport behavior degrades from the metallic to the insulating state after applying higher bias currents (&gt;31 mA) in vacuum. Furthermore, the metallic transport can be recovered by placing the degraded film in air. The results clearly suggest that the oxygen vacancy in the La0.8Ba0.2MnO3 films is controllable in different atmospheres, particularly with the aid of the Joule self-heating. According to the SEM images, we attribute the controlled oxygen vacancy to the nano-sized labyrinth pattern of the films, where the large surface-to-volume ratio plays a crucial role.

Highlights

Perovskite manganites have received extensive attention in recent years due to their novel physical properties and potential applications
The samples were heated at 100 ○C for 10 min in a furnace to drive off water
We have investigated the electric current induced Joule self-heating effects on the transport property of La0.8Ba0.2MnO3 ultrathin film deposited on the (001) LaAlO3 single crystal substrate prepared by the sol–gel method

Summary

Introduction

Perovskite manganites have received extensive attention in recent years due to their novel physical properties and potential applications. In order to investigate the current-induced effect on the LBMO film, bias current with various values was first applied to the sample for a few minutes at 40 K in a vacuum of 10−2 Pa. we measured temperature dependence of resistivity with a small current of 0.1 mA after each process of the bias current Ib. Figure 2(a) shows the resistivity–temperature (ρ–T) curves of the pristine state and those after applying different bias currents.

Results

Conclusion