Temperature-dependent formation and shrinkage of hollow shells in hemispherical Ag/Pd nanoparticles

Abstract

It is shown that both the growth and shrinkage of hollow shells in Ag/Pd hemispherical core-shell nanostructures take place at the same temperature. The crossover time, t _cr, between these regimes is shifted to lower values with increasing temperature. This result confirms that the growth and shrinkage regimes are controlled by the faster and slower diffusion coefficients (D _Ag and D _Pd), respectively. The pore radius, confirming recent theoretical predictions, linearly depends on the initial particle radius, and the slope of this straight line increases with the average composition of the faster component.

Keywords:

• hollow nanostructures
• stability
• interdiffusion
• Kirkendall effect

Acknowledgments

This work was supported by Grant No. CK 80126 of the Hungarian Scientific Research Found and by the TAMOP 4.2.1./B-09/1/KONV-2010-007 project, which is co-financed by the European Union and European Social Fund.