Tribochemical Decomposition of Light Ionic Hydrides at Room Temperature.
Tribochemical decomposition of magnesium hydride (MgH2) induced by deformation at room temperature was studied on a micrometric scale, in situ and in real time. During deformation, a near-full depletion of hydrogen in the micrometric affected zone is observed through an instantaneous (t < 1 s) and huge release of hydrogen (3-50 nmol/s). H release is related to a nonthermal decomposition process. After deformation, the remaining hydride is thermally decomposed at room temperature, exhibiting a much slower rate than during deformation. Confocal-microRaman spectroscopy of the mechanically affected zone was used to characterize the decomposition products. Decomposition was enhanced through the formation of the distorted structure of MgH2 with reduced crystal size by mechanical deformation.
†Spanish National Research Council, Institute "Eduardo Torroja" (IETCC-CSIC), C/Serrano Galvache 4, Madrid 28033, Spain.
Roman
R
Nevshupa
‡Department of Physics of Materials, Autónoma University of Madrid, Madrid 28049, Spain.
Jose Ramón
JR
Ares
‡Department of Physics of Materials, Autónoma University of Madrid, Madrid 28049, Spain.
Jose Francisco
JF
Fernández
§Spanish National Research Council, Institute of Ceramic and Glass (ICV-CSIC), C/Kelsen 5, Madrid 28049, Spain.
Adolfo
A
Del Campo
∥Spanish National Research Council, Institute of Material Science of Madrid (ICMM-CSIC), C/Sor Juana Inés de la Cruz 3, Madrid 28049, Spain.
Elisa
E
Roman
hydrogen kinetics; magnesium hydride; micro-Raman; microdeformation