In-situ infrared imaging methodology for measuring heterogeneous growth process of a hydride phase

In the paper we report on a new methodology, which allows measuring in-situ heterogeneous growth rates of hydride phase in films during metal-hydride phase transformation. This optical method is based on infrared imaging of a wedge-shaped thin film during hydrogen loading. In the paper the method is demonstrated for MG(98.4)Ti(1.6) wedge-shaped thin film and main conclusions are supported by results of transmission electron microscopy. The methodology combined with the structural characterizations verified fast formation of MgH(2) layer on top followed by drastically slower growth of the MgH(2) phase. The initial averaged growth rate of the MgH(2) phase was estimated as similar to 1.3 nm/s, and as similar to 0.03 nm/s subsequently. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.