Hydrogen Sorption in Layered Nanoporous GaSe Crystals.

Authors :: Kovalyuk, Z. D.
Bakhtinov, A. P.
Vodop'Yanov, V. N.
Zaslonkin, A. V.
Netyaga, V. V.
Source :: Carbon Nanomaterials in Clean Energy Hydrogen Systems; 2009, p765-777, 13p
Publication Year :: 2009
Abstract: By using the methods of atomic force microscopy (AFM) as well as infrared (IR) absorption and impedance spectroscopy the surface morphology, optical and electrical properties of layered GaSe crystals with nano-scale defects filled with hydrogen from gaseous phase are investigated. Hydrogen sorption is under investigations for layered GaSe crystals with surface defects different in morphology, density, and size. Changes in the impedance and IR spectra at hydrogen desorption from nano-porous H<subscript>x</subscript>GaSe crystals are investigated. It is found that there are resonance variations in frequency dependences of the impedance, a giant change of the conductivity along the C axis (even to 10<superscript>7</superscript> ÷ 10<superscript>8</superscript> times) typical for ˵semiconductor – metal″ transitions, and an intensive light scattering in the IR spectral range. These phenomena are related to polytype phase transitions occurring in ˵soft″ nano-porous H<subscript>x</subscript>GaSe crystals at the transition of the hydrogen from liquid state of aggregation to gaseous one. [ABSTRACT FROM AUTHOR]