Search for content and authors |
Thermodynamics of the Metal-Hydrogen System in DAC |
Marek Tkacz |
Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, Warszawa 01-224, Poland |
Abstract |
Application of diamond anvil cell (DAC) to the investigations of metal - hydrogen systems has extended the limit of hydrogen pressure by almost two orders of magnitude[1]. Due to the strong deviation from ideality, activity of hydrogen expressed as fugacity, could be increased by many orders of magnitude [2,3]. As a result chemical potential of hydrogen could be increased to the extent so far impossible to obtain, giving the possibility of synthesis of new hydrides and determination of thermodynamic properties of this compounds as hydrogen activity is well defined in DAC. By combining DAC with X-ray diffraction technique one can follow crystal structure and volume changes of the sample within DAC as function of hydrogen pressure. Since the incorporation of the hydrogen atom into metal lattice causes increase of the host lattice volume of about 2.9 A3 [4] calculated per metal atom, measurements of lattice volume allow for the calculation of hydrogen concentration in the metal.
|
Legal notice |
|
Related papers |
Presentation: oral at High Pressure School 2001 (4th), by Marek TkaczSee On-line Journal of High Pressure School 2001 (4th) Submitted: 2003-02-16 17:33 Revised: 2009-06-08 12:55 |