Novel device for simultaneous volumetric and X-rays diffraction measurements on metal-hydrogen systems

B. A. TALAGAÑIS

Trieste

Workshop; Joint IAEA – ICTP Advanced School on “Development and characterization of materials for hydrogen-based energy systems: Role of nuclear technology”; 2011

ICTP - IAEA, International Centre for Theoretical Physics - International Atomic Energy Agency

In order to characterize and improve hydrogen storage materials in systems where many phases can be formed, it is very helpful to be able to correlate hydrogen intake with a precise determination of the hydride phases involved in the process. The aim of this work is to present a simple, compact and low cost device that performs simultaneous X-ray diffraction and hydrogen sorption measurements. The small-size reactor chamber can stand up to 6000 kPa of internal pressure while the sample can be heated up to 450ºC in vacuum or hydrogen atmosphere, and can be mounted in the sample holder space of our X-rays diffractometer. The design process was assisted by finite elements modeling and by the use of mock-up prototypes in order to optimize thermal and under-load behaviors. The acquisition and control software was designed to perform simultaneous control and measurement of volumetric and X-rays diffraction parameters (reactor inner pressure, sample temperature, in/out hydrogen flow, goniometer position, step size, integration time and detected counts). Examples of phase identification using this new device during pressure-composition isotherms and thermal desorption spectroscopy are also presented.