反铁磁性
材料科学
坡莫合金
各向异性
异质结
氧化物
交换偏差
组态熵
凝聚态物理
熵(时间箭头)
磁各向异性
磁场
化学物理
热力学
磁化
化学
物理
量子力学
光电子学
冶金
作者
Peter Meisenheimer,T. J. Kratofil,John T. Heron
标识
DOI:10.1038/s41598-017-13810-5
摘要
Entropy-stabilized materials are stabilized by the configurational entropy of the constituents, rather than the enthalpy of formation of the compound. A unique benefit to entropy-stabilized materials is the increased solubility of elements, which opens a broad compositional space, with subsequent local chemical and structural disorder resulting from different atomic sizes and preferred coordinations of the constituents. Known entropy-stabilized oxides contain magnetically interesting constituents, however, the magnetic properties of the multi-component oxide have yet to be investigated. Here we examine the role of disorder and composition on the exchange anisotropy of permalloy/(Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O heterostructures. Anisotropic magnetic exchange and the presence of a critical blocking temperature indicates that the magnetic order of the entropy-stabilized oxides considered here is antiferromagnetic. Changing the composition of the oxide tunes the disorder, exchange field and magnetic anisotropy. Here, we exploit this tunability to enhance the strength of the exchange field by a factor of 10x at low temperatures, when compared to a permalloy/CoO heterostructure. Significant deviations from the rule of mixtures are observed in the structural and magnetic parameters, indicating that the crystal is dominated by configurational entropy. Our results reveal that the unique characteristics of entropy-stabilized materials can be utilized and tailored to engineer magnetic functional phenomena in oxide thin films.
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