Cross stacking faults in Zr(Fe,Cr)2 face-centered cubic Laves phase nanoparticle

Stacking faults (SFs) are mostly related to the glide of partial dislocations. Although the SFs have been extensively studied, the cross stacking faults (CSFs) have hardly been explored. In fact, for face-centered cubic (FCC) structure, the {1 1 1} family planes include four crossed close-packed planes. If the dislocations originate on the crossed planes, cross slips or CSFs can be induced. Here we report CSFs formed in the Zr(Fe,Cr)(2) FCC Laves phase nanoparticle (NP) in a zirconium alloy after shear deformation by means of transmission electron microscopy (TEM). Our results reveal that SFs mostly originate from the phase boundary by 1/6 <1 1 2> Shockley partial dislocations on crossed close-packed planes. More importantly, the driving force of CSFs was further discussed. Finally, we propose a model for the formation of CSFs in the FCC NP. That is: when the loading is parallel or close to <0 0 1> directions, the CSFs can be induced in the FCC crystals. Knowledge about our investigations here will provide a fundamental understanding of the CSFs.