Ming Yan,Jiangtao Huang,Mengliu Yang,Hao Zhang,Yu Zhu,Nengyu Zhou,Juan Wang
MAX phases are layered ternary carbides and nitrides with unique properties, doping transition metals in it is attracting significant attentions for the processing of this relatively new class of materials. In this paper, a magnetic solid solution MAX phase V 2 (Sn 1− x A x )C ( A = Mn, Fe, Co) was synthesized by doping Mn/Fe/Co atoms into V 2 SnC by pressure-less sintering. The XRD results show that when x = 0.4, the characteristic peak shifts to the right, and the substitution reaches saturation. SEM and TEM show that doping does not change the original layered morphology and hexagonal crystal form, but only the lattice constants decrease slightly. Magnetic test results indicate that V 2 (Sn 1− x A x )C is a typical low-temperature magnetic material with a Curie temperature around 60 K, and the magnetization increases with the increase of doping amount. Moreover, we explained the reasons of V 2 SnC doping A-site instead of M-site and the changing trend of the magnetic moments by first-principles calculations, which are consistent with the experimental results.
Li Youbing,Ma Guoliang,Shao Hui,Xiao Peng,Lu Jun,Xu Jin,Hou Jinrong,Chen Ke,Zhang Xiao,Li Mian,Persson Per O. Å.,Hultman Lars,Eklund Per,Du Shiyu,Chai Zhifang,Huang Zhengren,Jin Na,Ma Jiwei,Liu Ying,Lin Zifeng,Huang Qing
Small size V 2 SnC MAX phase was prepared by the molten salt method.
V 2 SnC MAX phase electrode is able to deliver high gravimetric capacity up to 490 mAh g −1 and volumetric capacity of 570 mAh cm −3
A charge storage mechanism with V 2 C-Li redox and Sn–Li alloying dual reactions was proposed
Yan Ming,Deng Yuxiao,Yan Zhuanlong,Li Hongyu,Cao Mengyang
This study reported the synthesis of magnetic solid solutions V 2 (A x B y Sn 1− x − y )C (where A and B are Mn, Fe, or Co) MAX phases. These materials were prepared by incorporating magnetic elements into the V 2 SnC MAX phase via pressure-less sintering at 1 000 °C for 3 hours. XRD analysis reveals that the composition with x = y = 0.2 exhibits a shift of diffraction peaks to higher angles, indicating lattice parameter changes, and achieves the highest phase purity with the maximum solid solution limit, further increases in the dopant content led to the formation of impurities. While the solid solution of magnetic elements preserves the characteristic layered structure of the MAX phase, it successfully induces magnetic properties. The magnetic transition temperatures for these solid solutions ranges from 61 to 200 K. Specifically, V 2 (Mn x Co y Sn 1− x − y )C demonstrated hard magnetic characteristics, with a high saturation magnetization (6.536 emu/g) and large remanence (4.236 emu/g). In contrast, V 2 (Mn x Fe y Sn 1− x − y )C and V 2 (Fe x Co y Sn 1− x − y )C exhibits soft magnetic behavior, evidenced by their narrow hysteresis loops and low coercivity. Their saturation magnetization values are 3.80 and 1.784 emu/g, respectively. The distinctly “S”-shaped hysteresis loop of V 2 (Fe x Co y Sn 1− x − y )C further confirms its soft magnetic nature.
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