Field dependence of magnetization for a thin ferromagnetic film on rough antiferromagnetic surface

2014

This is a theoretical investigation of the exchange bias phenomenon, and the properties of a thin magnetic film's magnetization hysteresis loop, on the rough surface of a hard-magnetic antiferromagnet. An interface model with a periodic structure of atomic steps is presented. These atomic steps are associated with a spatially inhomogeneous distribution of the ferromagnetic film magnetization, akin to a system of domain walls. This structure leads to a complicated external field dependence of magnetization: the hysteresis curve can assume an asymmetrical shape and "fall apart" into two hysteresis loops, divided by a "horizontal plateau," or an area with constant fieldindependent magnetization. Such field dependence behavior has been recently observed experimentally in different ferro/antiferromagnet systems. The field dependence of magnetization has been obtained analytically using the long-wave approximation for various characteristics of ferromagnetic film (its thickness, values of exchange interaction, and magnetic anisotropy), and the interface (the period of the inhomogeneous structure, and exchange interaction through the interface). The analytical results are confirmed by numerical calculations for the corresponding discrete model with a more complex interface structure. V

Section: Model Formulationmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Properties of ferromagnetic film hysteresis, on the surface of a hard-magnetic antiferromagnet, with a domain structure

2014

“…3(б). Такая одномерная задача исследовалась ранее в применении к слоистым ФМ/АФМ системам для нескомпенсированных ГР в [10,11] и скомпенсированных и неупорядоченных границ в [14,15].…”

Section: перемагничивание радиально симметричного кластера большого рunclassified

Exchange bias effect in antiferromagnets containing ferromagnetic clusters

2018

This study offers an explanation for the occurrence of magnetization exchange bias in antiferromagnets with ferromagnetic inclusions during pre-cooling the system in a magnetic field. The ferromagnetic (FM) subsystem ordered in this field at the Néel temperature leads to an inhomogeneous state of the antiferromagnetic (AFM) matrix with the finite mean effective field at the FM/AFM interface. This field causes exchange bias in the dependence M = M(H) during further remagnetization of the heterogeneous system. To describe the proposed scenario for such an effect, a simple model of a two-dimensional system with round inclusions of the FM phase was considered. Using numerical calculations and previously obtained analytical results, the study determines magnetization dependencies on the external field, which qualitatively explains the features of exchange bias in experimentally studied heterogeneous systems.

“…15 In our previous study, we proposed a model of point magnetic contacts at the FM/AFM interface, in order to explain the EB effect in a two-layer system with a rough interface. 16 In this study we are examining a trilayer structure with one ideal and one rough FM/AFM interface (Fig. 4).…”

Section: The Influence Of Defects On the Properties Of Magnetization mentioning

confidence: 99%

Model of exchange bias in a trilayer FM/AFM/FM structure

2015

A theoretical examination of the properties of the exchange bias phenomenon for sandwich FM/AFM/FM structures, which are actively studied in experiments. Magnetization dependences on the external magnetic field are obtained under the proposed discrete model of ferromagnetic layers of such multilayer structures. It is shown that the magnetization field dependences have a horizontal plateau, a splitting of the hysteresis loop, and asymmetry. We examine the influence of the interface defects on the exchange bias phenomenon and its features. The results are qualitatively consistent with experimental data.