Exchange Bias Effect in LaFeO3: La0.7Ca0.3MnO3 Composite Thin Films

Feng Wang,Wei Fu,Chengming Jiang,Jijie Huang,Junxiao Li

doi:10.3390/coatings11091125

Abstract

Composite thin films arouse great interests owing to the multifunctionalities and heterointerface induced physical property tailoring. The exchange bias effect aroused from the ferromagnetic (FM)–antiferromagnetic (AFM) heterointerface is applicable in various applications such as magnetic storage. In this work, (LaFeO3)x:(La0.7Ca0.3MnO3)1−x composite thin films have been deposited via pulsed laser deposition (PLD) and the exchange bias effect was investigated. In such system, LaFeO3 (LFO) is an antiferromagnet while La0.7Ca0.3MnO3 (LCMO) is a ferromagnet, which results in the exchange bias interfacial coupling at the FM/AFM interface. The composition variation of the two phases could lead to the exchange bias field (HEB) tuning in the composite system. This work demonstrates a new composite thin film system with FM-AFM interfacial exchange coupling, which could be applied in various spintronic applications.

Highlights

Exchange bias (EB) describes the pinning of the magnetic dipoles due to the interfacial exchange coupling between ferromagnetic and antiferromagnetic (AFM) components after cooling through Néel temperature (TN) of the antiferromagnets, which results in the shift of the hysteresis loop
Standard θ–2θ X-ray diffraction (XRD) scans were characterized on the LFO:LCMO thin films with different compositions, as shown in Figure 1a–c for LFO0.33LCMO0.67, LFO0.5LCMO0.5 and LFO0.67LCMO0.33, respectively
LFO (00l) and LCMO (00l) peaks can be observed, which indicates the textured growth of both phases and that no impurity is formed in the composite films

Summary

Introduction

Exchange bias (EB) describes the pinning of the magnetic dipoles due to the interfacial exchange coupling between ferromagnetic (ferrimagnetic, FM) and antiferromagnetic (AFM) components after cooling through Néel temperature (TN) of the antiferromagnets, which results in the shift of the hysteresis loop. The FM/AFM exchange coupling in thin film could be achieved in the following forms: multilayer thin film, vertically aligned nanocomposite thin film, solid solution (or composite) thin film or even a singlephase thin film [10,11,12,13]. Different from the transverse FM/AFM interface in multilayers, VAN thin film presents FM/AFM coupling along the vertical direction, which is beneficial to realize perpendicular EB effect. Solid solution thin films with FM and AFM phases can induce the EB effect by the FM/AFM exchange coupling in nanoscale interface [12]. The EB effect has been obtained in variety of thin films with different nanostructures, there are still plenty of material systems and geometries needing further investigation

Methods

Results

Conclusion