室温交换偏置效应的研究进展

Research Progress of Exchange Bias Effect at Room Temperature

交换偏置效应是指材料在外加磁场或不加磁场冷却后,磁滞回线沿磁场轴发生偏移的现象。它已成为研究信息存储技术的重要理论基础,在诸如磁传感器、磁存储读头以及磁自旋阀等电子器件中有着不可或缺的作用。因此,近年来引起了研究者极大的关注和研究。交换偏置效应广泛存在于纳米核壳结构的颗粒,多层膜体系以及块状合金中。但是,目前研究的具有交换偏置效应的绝大多数材料体系都在低温下(T≤50 K)才可以出现交换偏置效应,从而在很大程度上限制了交换偏置效应在实际中的应用。经过多年的探索和研究,在部分薄膜体系、纳米核壳结构和近补偿的亚铁磁体系得到了室温交换偏置效应。本文将对近年来室温下的交换偏置效应研究进行详细的整理和总结,分析了现阶段室温交换偏置效应研究中存在的问题及面临的挑战,希望能为室温交换偏置效应体系的研究提供参考。

The exchange bias effect refers to the phenomenon that the hysteresis loop of the material is shifted along the magnetic field axis after the material is cooled with or without the extra magnetic field.It has become an important theoretical basis for research on information storage technology,and plays an indispensable role in electronic devices such as electromagnetic sensors,magnetic read heads,and magnetic spin valves.Therefore,in recent years,researchers have attracted great attention and research.The exchange bias effect is widely present in nano-core@shell particles,multilayer film systems and bulk alloys.However,most of the exchange bias systems should be investigated at low temperature(T≤50 K),which limits the application of exchange bias effect.After years of exploration and research,the room temperature exchange bias effect has been obtained in some thin film systems,nano-core@shell particles,multilayer film systems and nearly-compensated ferrimagnetic systems.In this paper,the investigation of room temperature exchange bias effect in recent years is summarized in detail,and the existing problems and challenges are analyzed in the hope of providing references for the study of exchange bias systems at room temperature.