On the size dependence of the critical point of nanoscale interstitial solid sol

2019-11-09 02:09:33

potential concentration critical chemical dependence

责任者: Weissmuller, J.;Lemier, C. 单位: Inst. fur Nanotechnol., Forschungszentrum Karlsruhe, Germany 来源出处: Philosophical Magazine Letters(Philos. Mag. Lett. (UK)),2000/06/,80(6):411-18 摘要: It is shown that a size dependence of the critical temperature Tc of the miscibility gap in nanocrystalline and nanoscale particle interstitial solid solutions results from stress owing to elastic interaction of the bulk with layers of material at the grain boundaries or surfaces which have a small solute susceptibility (i.e. a weak dependence of the concentration on the chemical potential) at the phase transition. When the volume fraction occupied by the interfacial layers is not too large, then the changes in Tc and in the critical concentration xc can be predicted on the basis of a series expansion of the solute chemical potential in the bulk about the critical point. The model can be extended to free-standing thin films and coherent multilayers. The dependence of the pressure on the hydrogen concentration in the crystal lattice of nanocrystalline palladium-hydrogen is measured on the basis of X-ray diffraction data. The result agrees with the predictions of the theory 关键词: chemical potential;critical points;grain boundaries;interstitials;nanostructured materials;palladium compounds;solid solutions;solubility;size dependence;critical point;nanoscale interstitial solid solutions;critical temperature;miscibility gap;nanocrystalline particle interstitial solid solutions;stress;elastic interaction;grain boundaries;solute susceptibility;chemical potential;phase transition;interfacial layers;critical concentration;series expansion;solute chemical potential;free-standing thin films;coherent multilayers;hydrogen concentration;nanocrystalline palladium-hydrogen;X-ray diffraction data;Pd-H