Strain Analysis of AuxCu1-x−Cu2O Biphase Nanoparticles with Heteroepitaxial Interface

Epitaxially coherent Au x Cu 1 - x −Cu 2 O biphase nanoparticles ( x = 0.83) were grown in free space by oxidizing Au y Cu 1 - y alloy nanoparticles ( y = 0.46) above their melting temperature. Electron-microscopic studies revealed that Au 0.83 Cu 0.17 and Cu 2 O dome-shape nanocrystals are conjunct via a (110) heteroepitaxial interface with no crystallographic rotation to form a prolate-spheroid shape. It was observed that the misfit strain from 6.5% lattice mismatch is taken up by locally deforming both Cu 2 O and Au 0.83 Cu 0.17 near the interface. The observed strain profiles were reproduced quantitatively using continuum theory modified with a semiempirical fitting parameter.