Extended x-ray absorption fine structure spectroscopy, x-ray diffraction and transmission electron microscopy were used to analyze the Nb coordination and clustering in Nb-doped (5 at. %) h-Mg film samples deposited by rf magnetron sputtering. Results show that the catalytic effect of the Nb doping in the H-2 absorption and desorption kinetics is connected with the formation of Nb nanoclusters dispersed in the host matrix. The H-2 desorption from beta-MgH2 is favored by local elastic stresses produced by beta-NbH0.89 clusters on the MgH2 matrix that reduces the stability of the hydride phase and by preferential paths in the nanocomposite hydride. (c) 2005 American Institute of Physics.
Nb clusters formation in Nb-doped magnesium hydride
2005
Abstract
Extended x-ray absorption fine structure spectroscopy, x-ray diffraction and transmission electron microscopy were used to analyze the Nb coordination and clustering in Nb-doped (5 at. %) h-Mg film samples deposited by rf magnetron sputtering. Results show that the catalytic effect of the Nb doping in the H-2 absorption and desorption kinetics is connected with the formation of Nb nanoclusters dispersed in the host matrix. The H-2 desorption from beta-MgH2 is favored by local elastic stresses produced by beta-NbH0.89 clusters on the MgH2 matrix that reduces the stability of the hydride phase and by preferential paths in the nanocomposite hydride. (c) 2005 American Institute of Physics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
