Theoretical prediction, synthesis, and crystal structure determination of new MAX phase compound V2SnC

• 作者: Anna JIANG Chunfeng HU Haiming ZHANG Johanna ROS(E)N Jun LU Qiang Xu Quanzheng TAO Salvatore GRASSO Yanchun ZHOU Yunhui NIU
• 来源期刊: 先进陶瓷（英文版）
• 年，卷（期）: 2020,（4）
• 所属期刊栏目: Research Article
• 页码范围: 481-492
• 页数: 12页
• 语种: 英文

摘要

Guided by the theoretical prediction,a new MAX phase V2SnC was synthesized experimentally for the first time by reaction of V,Sn,and C mixtures at 1000 ℃.The chemical composition and crystal structure of this new compound were identified by the cross-check combination of first-principles calculations,X-ray diffraction (XRD),energy dispersive X-ray spectroscopy (EDS),and high resolution scanning transmission electron microscopy (HR-STEM).The stacking sequence of V2C and Sn layers results in a crystal structure of space group P63/mmc.The a-and c-lattice parameters,which were determined by the Rietveld analysis of powder XRD pattern,are 0.2981(0) nm and 1.3470(6) nm,respectively.The atomic positions are V at 4f (1/3,2/3,0.0776(5)),Sn at 2d (2/3,1/3,1/4),and C at 2a (0,0,0).A new set of XRD data of V2SnC was also obtained.Theoretical calculations suggest that this new compound is stable with negative formation energy and formation enthalpy,satisfied Born-Huang criteria of mechanical stability,and positive phonon branches over the Brillouin zone.It also has low shear deformation resistance c44 (second-order elastic constant,cij) and shear modulus (G),positive Cauchy pressure,and low Pugh's ratio (G/B =0.500 ＜ 0.571),which is regarded as a quasi-ductile MAX phase.The mechanism underpinning the quasi-ductility is associated with the presence of a metallic bond.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	Salvatore GRASSO		2	0	0.0	0.0
2	Qiang Xu		1	0	0.0	0.0
3	Yanchun ZHOU		1	0	0.0	0.0
4	Haiming ZHANG		1	0	0.0	0.0
5	Anna JIANG		1	0	0.0	0.0
6	Quanzheng TAO		1	0	0.0	0.0
7	Jun LU		1	0	0.0	0.0
8	Johanna ROS(E)N		1	0	0.0	0.0
9	Yunhui NIU		1	0	0.0	0.0
10	Chunfeng HU		1	0	0.0	0.0