Non-conventional synthesis and magnetic properties of MAX phases (Cr/Mn)2AlC and (Cr/Fe)2AlC
Non-conventional synthesis and magnetic properties of MAX phases (Cr/Mn)2AlC and (Cr/Fe)2AlC
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DOI：
10.1039/c7tc00112f
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发表时间：
2017-06-21
影响因子：
6.4
通讯作者：
Birkel, Christina S.
中科院分区：
文献类型：
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作者：
Hamm, Christin M.;Bocarsly, Joshua D.;Birkel, Christina S.
在磁性MAX相的理论预测之后的几年里，许多这样的材料已经被实验报道，特别是以薄膜的形式。然而，由于相对较少的研究，我们才刚刚开始发现与这类材料相关的有趣的磁性。用后期过渡金属制备大块MAX相已被证明是特别具有挑战性的。因此，有很大的需要发展的合成策略，以获得相应的材料在适当数量的磁研究。本研究采用微波加热和火花等离子烧结等非常规合成方法制备了大块Mn和fe取代的Cr2AlC。同步加速器x射线衍射结合详细的元素分析证实了MAX相与后期过渡金属的成功掺杂，并阐明了获得的致密材料的微观结构。Fe-57穆斯堡尔谱数据显示了掺杂MAX相和含fe次级相的信号。基于PPMS和SQUID测量，在已有研究的背景下讨论了所得样品的非平凡磁性行为。
A few years after the theoretical prediction of magnetic MAX phases, a number of such materials have been experimentally reported, especially in the form of thin films. Yet, due to a relatively small number of studies, we have only just begun to discover the intriguing magnetic properties that are associated with this class of materials. The preparation of bulk MAX phases with later transition metals has been proven to be particularly challenging. Consequentially, there is a great need to develop synthetic strategies to obtain the respective materials in suitable quantities for magnetic investigations. Here, bulk Mn- and Fe-substituted Cr2AlC are prepared using non-conventional synthesis methods such as microwave heating and spark plasma sintering. Synchrotron X-ray diffraction coupled with detailed elemental analyses is used to confirm the successful doping of the MAX phase with the later transition metals as well as to elucidate the microstructure of the obtained dense materials. Fe-57 Mossbauer spectroscopy data are presented showing signals of the doped MAX phase and Fe-containing secondary phases. Based on PPMS and SQUID measurements the non-trivial magnetic behavior of the obtained samples is discussed in the context of the existing studies.