Structural, magnetic and electrical transport properties of non-conventionally prepared MAX phases V2AlC and (V/Mn)2AlC
Structural, magnetic and electrical transport properties of non-conventionally prepared MAX phases V2AlC and (V/Mn)2AlC
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DOI：
10.1039/c7qm00488e
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发表时间：
2017
影响因子：
7
通讯作者：
C. M. Hamm;M. Dürrschnabel;L. Molina‐Luna;R. Salikhov;D. Spoddig;M. Farle;U. Wiedwald;Christina S. Birkel
中科院分区：
文献类型：
--
作者：
C. M. Hamm;M. Dürrschnabel;L. Molina‐Luna;R. Salikhov;D. Spoddig;M. Farle;U. Wiedwald;Christina S. Birkel
大量的磁基态沿着与有趣的磁性能已被报道在薄膜中的锰含MAX相。然而，较少的结果，因此，在该地区的散装磁MAX阶段存在的知识较少，导致许多开放的研究问题，仍然没有答案。高品质材料的合成是关键，这里实现了块状V2AlC及其Mn掺杂的类似物，通过微波加热和放电等离子烧结。通过结构和显微结构研究对所获得的材料进行了仔细的表征，结果表明Mn掺杂的V2AlC样品中的平均Mn含量为2%，对应于（V0.96±0.02Mn0.04±0.02）2AlC的平均化学组成。虽然母体MAX相以及具有标称最低Mn含量的样品基本上是单相的，但具有较高Mn水平的样品表现出富Mn侧相。这些是最有可能负责相应的散装材料的铁磁行为。此外，我们还发现了母体化合物V2AlC的Pauli顺磁性以及（V0.96±0.02Mn0.04±0.02）2AlC的Pauli和Langevin顺磁性的组合.对于后者，每个M原子可以提取μM = 0.2（2）μB的磁矩。
A plethora of magnetic ground states along with intriguing magnetic properties have been reported in thin films of Mn-containing MAX phases. However, fewer results and therefore less knowledge in the area of bulk magnetic MAX phases exist resulting in many open research questions that still remain unanswered. Synthesis of high quality materials is key and is here achieved for bulk V2AlC and its Mn-doped analogs by means of microwave heating and spark plasma sintering. The obtained materials are carefully characterized by structural and microstructural investigations resulting in an average Mn-content of 2% corresponding to the mean chemical composition of (V0.96±0.02Mn0.04±0.02)2AlC in the Mn-doped V2AlC samples. While the parent MAX phase as well as the sample with the nominally lowest Mn-content are obtained essentially single-phase, samples with higher Mn-levels exhibit Mn-rich side phases. These are most likely responsible for the ferromagnetic behavior of the corresponding bulk materials. Besides, we show Pauli paramagnetism of the parent compound V2AlC and a combination of Pauli and Langevin paramagnetism in (V0.96±0.02Mn0.04±0.02)2AlC. For the latter, a magnetic moment of μM = 0.2(2) μB per M atom can be extracted.