High-entropy oxides: An emerging prospect for magnetic rare-earth transition metal perovskites
High-entropy oxides: An emerging prospect for magnetic rare-earth transition metal perovskites
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DOI：
10.1103/physrevmaterials.3.034406
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发表时间：
2019-01
影响因子：
3.4
通讯作者：
R. Witte;Abhishek Sarkar;R. Kruk;B. Eggert;R. Brand;H. Wende;H. Hahn
中科院分区：
文献类型：
--
作者：
R. Witte;Abhishek Sarkar;R. Kruk;B. Eggert;R. Brand;H. Wende;H. Hahn
结果表明，含有等摩尔比的多个过渡和/或稀土元素的氧化物陶瓷具有很强的结晶倾向，易于形成简单的单相结构，并由高构型熵稳定。与金属合金系统类似，这些氧化物被称为高熵氧化物（HEOs）。HEO概念允许在多元素相图中访问迄今为止未知的区域。在已经实现的结构中，有一类高度复杂的稀土过渡元素钙钛矿。通过应用高熵稳定的创新概念产生的这类迷人的材料提供了一个新的和多方面的研究空间，有望发现前所未有的特性和现象。本研究首次对这类新型材料中所选化合物的磁性进行了研究。为了了解磁性交换与体系中高度化学无序性之间的相互作用，将直流和交流磁强计综合研究与元素特异光谱相结合。我们在单相材料中观察到主要的反铁磁行为，并结合可能源于反铁磁矩阵中的小铁磁团簇或构型的小铁磁贡献。从长远的角度来看，建议采用高通量的方法，包括实验和理论相结合的方法来筛选这类化合物的性质。
It has been shown that oxide ceramics containing multiple transition and/or rare-earth elements in equimolar ratios have a strong tendency to crystallize in simple single phase structures, stabilized by the high configurational entropy. In analogy to the metallic alloy systems, these oxides are denoted high entropy oxides (HEOs). The HEO concept allows to access hitherto uncharted areas in the multi-element phase diagram. Among the already realized structures there is the highly complex class of rare earth - transition element perovskites. This fascinating class of materials generated by applying the innovative concept of high entropy stabilization provides a new and manyfold research space with promise of discoveries of unprecedented properties and phenomena. The present study provides a first investigation of the magnetic properties of selected compounds of this novel class of materials. Comprehensive studies by DC and AC magnetometry are combined with element specific spectroscopy in order to understand the interplay between magnetic exchange and the high degree of chemical disorder in the systems. We observe a predominant antiferromagnetic behavior in the single phase materials, combined with a small ferromagnetic contribution possibly stemming from small ferromagnetic clusters or configurations in the antiferromagnetic matrix. In the long term perspective it is proposed to screen the properties of this family of compounds with high throughput methods, including combined experimental and theoretical approaches.