Nanoprecipitates are crucial for determining diversse properties of nanoheterogeneous materials. For instance, the tetragonal L60 nanoprecipitates dispersing in the body‐centered cubic A2 matrix yield the large magnetostrictive effect in Fe‐Ga alloys. Nanoprecipitates are usually coarsened under thermally activated circumstances in most of nanoheterogenous materials, which typically leads to the degeneration of the material performance. This is a bottleneck issue for the long‐time usage of nanoheterogeneous materials under thermally activated conditions. In this study, it is found that the L60 nanoprecipitates in large‐magnetostriction Fe81Ga19 single crystals are superiorly stable under accelerating aging experiments, as evidenced by the almost unchanged phase structure, average size, volume fraction and tetragonality. Accordingly, the large magnetostrictive effect is highly stable upon long‐time thermal excitations. Systematic studies combing experimental and theoretical efforts reveal that the stronger chemical bonding between the L60 nanoprecipitates and the A2 matrix relative to the original chemical bonding within the A2 matrix results in a strikingly negative interfacial energy that stabilizes the nanoprecipitates. Thus, this work provides a promising strategy for stabilizing nanoprecipitates via interfacial chemical bonding strengthening induced negative interfacial energy and hence achieving highly stable performance of nanoheterogeneous materials.

中文翻译：

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纳米异质 Fe81Ga19 合金通过负界面能使纳米析出物不粗化而实现高度稳定的磁致伸缩


纳米沉淀物对于确定纳米异质材料的多样性特性至关重要。例如，分散在体心立方 A2 基体中的四方 L60 纳米析出物在 Fe-Ga 合金中产生较大的磁致伸缩效应。在大多数纳米异质材料中，纳米沉淀物通常在热活化情况下变得粗化，这通常会导致材料性能退化。这是在热活化条件下长期使用纳米异质材料的瓶颈问题。本研究发现，大磁致伸缩 Fe81Ga19 单晶中的 L60 纳米析出物在加速老化实验下具有优异的稳定性，几乎不变的相结构、平均尺寸、体积分数和四方性证明了这一点。因此，大磁致伸缩效应在长时间热激发下高度稳定。结合实验和理论工作的系统研究表明，相对于 A2 基质内的原始化学键，L60 纳米沉淀物和 A2 基质之间更强的化学键导致显着的负界面能，从而稳定纳米沉淀物。因此，这项工作提供了一种很有前途的策略，通过界面化学键强化诱导负界面能来稳定纳米沉淀物，从而实现纳米异质材料的高度稳定性能。