J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (4): 530-534.DOI: 10.1016/j.jmst.2018.10.006

• Orginal Article • Previous Articles     Next Articles

Crystal structure of Cr4AlB4: A new MAB phase compound discovered in Cr-Al-B system

Haiming Zhangab, Fu-zhi Daia, Huimin Xianga, Zhili Zhangb, Yanchun Zhoua*()   

  1. a Science and Technology on Advanced Functional Composite Laboratory, Aerospace Research Institute of Materials & Processing Technology, No. 1 South Dahongmen Road, Beijing, 100076, China;
    b School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China
  • Received:2018-09-21 Revised:2018-09-28 Accepted:2018-09-30 Online:2019-04-05 Published:2019-01-28
  • Contact: Zhou Yanchun

Abstract:

In this communication, the crystal structure of Cr4AlB4, a new MAB phase compound (where M is a transition metal, A is Al or Si, B is boron) discovered in Cr-Al-B system is reported. This new MAB phase was synthesized from a mixture of CrB and Al powders at 1000 °C and its crystal structure was determined by a combination of X-ray diffraction, first-principles calculations and energy dispersive X-ray spectroscopy (EDS). Cr4AlB4 crystallizes in an orthorhombic structure with Immm space group. The lattice constants are a = 2.9343(6) ?, b = 18.8911(0) ?, c = 2.9733(7) ?, and the atomic positions are Cr1 at 4g (0, 0.2936(5), 0), Cr2 at 4h (0.5, 0.5859(7), 0), Al at 2b (0, 0.5, 0.5), B1 at 4h (0, 0.3839(8), 0.5) and B2 at 4g (0.5, 0.6646(2), 0.5).

Key words: Cr4AlB4, MAB phases, Crystal structure, Layered ternary borides, Ultrahigh temperature ceramics