纳米碳化钒对MnAlC合金结构和磁性的影响。

Influence of nano-VC on the structural and magnetic properties of MnAlC-alloy.

作者信息

Shtender Vitalii, Stopfel Henry, Hedlund Daniel, Karlsson Dennis, Pothala Rajasekhar, Skårman Björn, Olsson Fredrik, Vidarsson Hilmar, Andersson Gabriella, Svedlindh Peter, Sahlberg Martin

机构信息

Ångström Laboratory, Department of Chemistry, Uppsala University, Box 538, 751 21, Uppsala, Sweden.

Department of Materials Science and Engineering, Uppsala University, Box 35, 751 03, Uppsala, Sweden.

出版信息

Sci Rep. 2021 Jul 14;11(1):14453. doi: 10.1038/s41598-021-93395-2.

DOI:10.1038/s41598-021-93395-2

PMID:34262064

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8280156/

Abstract

Alloys of MnAlC with additions of VC nano-particles have been synthesized and their properties evaluated. The MnAlC(VC) (x = 0.25, 0.5 and 1) alloys have been prepared by induction melting resulting in a high content of the ferromagnetic τ-phase (> 94 wt.%). Powder X-ray diffraction indicates that nano-VC can be dissolved in the alloy matrix up to 1 at.%. On the other side, metallography investigations by scanning electron microscopy and scanning transmission electron microscope show inclusions of the nanosized additives in the microstructure. The effect of nano-VC on the grain and twin boundaries has been studied by electron backscattering diffraction. The magnetization has been measured by magnetometry up to 9 T while the domain structure has been studied using both magnetic force microscopy as well as Kerr-microscopy. For nano-VC contents above 0.25 at.%, a clear increase of the coercive force is observed, from 57 to 71 kA/m. The optimum appears to be for 0.5 at.% nano-VC which shows a 25% increase in coercive force without losing any saturation magnetization. This independent increase in coercivity is believed to originate from the nano-VC reducing the overall magnetic domain size. Overall, we observe that addition of nano-VC could be an interesting route to increase the coercive force of MnAl, without sacrificing saturation magnetization.

摘要

已合成了添加VC纳米颗粒的MnAlC合金，并对其性能进行了评估。通过感应熔炼制备了MnAlC(VC)（x = 0.25、0.5和1）合金，得到了高含量的铁磁τ相（> 94 wt.%）。粉末X射线衍射表明，纳米VC在合金基体中的溶解度可达1 at.%。另一方面，通过扫描电子显微镜和扫描透射电子显微镜进行的金相研究表明，微观结构中存在纳米尺寸添加剂的夹杂物。利用电子背散射衍射研究了纳米VC对晶粒和孪晶界的影响。通过磁强计测量了高达9 T的磁化强度，同时使用磁力显微镜和克尔显微镜研究了磁畴结构。当纳米VC含量高于0.25 at.%时，矫顽力明显增加，从57 kA/m增加到71 kA/m。最佳含量似乎是0.5 at.%的纳米VC，其矫顽力增加了25%，同时没有损失任何饱和磁化强度。据信，矫顽力的这种独立增加源于纳米VC减小了整体磁畴尺寸。总体而言，我们观察到添加纳米VC可能是一种在不牺牲饱和磁化强度的情况下提高MnAl矫顽力的有趣途径。