Ames Laboratory; Physics and Astronomy
Ames Laboratory, Physics and Astronomy
The plastic deformation and fracture mechanisms in single-crystalline CaFe2As2 has been studied using nanoindentation and density functional theory simulations. CaFe2As2 single crystals were grown in a Sn-flux, resulting in homogeneous and nearly defect-free crystals. Nanoindentation along the  direction produces strain bursts, radial cracking, and lateral cracking. Ideal cleavage simulations along the  and  directions using density functional theory calculations revealed that cleavage along the  direction requires a much lower stress than cleavage along the  direction. This strong anisotropy of cleavage strength implies that CaFe2As2 has an atomic-scale layered structure, which typically exhibits lateral cracking during nanoindentation. This special layered structure results from weak atomic bonding between the (001) Ca and Fe2As2 layers.
Department of Energy Subject Categories
36 MATERIALS SCIENCE
Iowa State University Digital Repository, Ames IA (United States)
Available for download on Wednesday, April 10, 2019