https://doi.org/10.1140/epjb/e2013-30909-6
Regular Article
Ab initio study of I2 and T2 stacking faults in C14 Laves phase MgZn2
1
School of Chemistry and Chemical Engineering, Guangxi
University, Nanning
530004, P.R.
China
2
Department of Physics, Xiangtan University,
Hunan Province
411105, P.R.
China
3
Light Alloy Net Forming National Engineering Research Center,
School of Materials Science and Engineering, Shanghai Jiaotong
University, Shanghai
200030, P.R.
China
a e-mail: tangbiyu@gxu.edu.cn
Received:
7
October
2012
Received in final form:
4
February
2013
Published online:
24
April
2013
Based on the synchroshear mechanism, the formation of intrinsic stacking fault I2 and twin-like stacking fault T2 in C14 Laves phases has been modeled in detail and the generalised stacking fault energy curve of I2 and T2 for C14 Laves phase MgZn2 has been calculated from first-principles. The results demonstrate that the unstable stacking fault energy of I2 by synchroshear is still very large, and the stable stacking fault energy of I2 is higher in comparison with pure Mg implying that the formation of I2 stacking fault in MgZn2 is difficult. Starting with the I2 configuration, the T2 stacking fault can be formed by an additional synchroshear. The unstable and stable stacking fault energies of T2 are only slightly larger than those of I2, implying that the formation of T2 may be essentially similar to that of I2. From the obtained generalised stacking fault energy, the relevant deformation mechanism of MgZn2 is also discussed. Finally, the electronic structure during synchroshear process is further studied.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2013