Please use this identifier to cite or link to this item: https://apo.ansto.gov.au/dspace/handle/10238/11663
Title: Development of a new instrument to observe time-resolved neutron diffraction intensities in association with phase transitions
Other Titles: Time-resolved studies of neutron diffraction intensities in association with phase transitions
Authors: Daniels, JE
Studer, AJ
Finlayson, TR
Hagen, ME
Keywords: Neutron diffraction
Phase transformations
Kinetics
HIFAR Reactor
ANSTO
Spectrometers
Electric potential
Issue Date: 31-Jan-2005
Publisher: Australian Institute of Physics
Citation: Daniels, J. E., Studer, A. J., Finlayson, T. R., & Hagen, M. E. (2005). Development of a new instrument to observe time-resolved neutron diffraction intensities in association with phase transitions. Paper presented to the 29th Condensed Matter and Materials Meeting, "Australian Institute of Physics Sixteenth Biennial Congress", Canberra, 2005, 31 January - 4 February 2005. Retrieved from: https://www.physics.org.au/wp-content/uploads/cmm/2005/05._Daniels_AIP2005_CMMSP.pdf
Abstract: The study of time-resolved diffraction intensities during a phase transition is important for gaining an understanding of the kinetics involved. Unfortunately the flux needed in order to achieve good counting statistics for a diffraction experiment during a single phase transition is very high. This problem is then compounded if the time scales which need to be observed are very small. Therefore techniques which can take advantage of the reversibility of some phase transitions are potentially beneficial in order to build up statistics. Stroboscopic techniques have been used in recent times to observe diffraction peak intensities with very good time resolution during the application of some type of perturbing field, driving a transition. Most commonly, and as will be the case with this instrument, high electric fields are used to switch single-crystal samples between their paraelectric and ferroelectric phases. Diffraction peaks are observed as a function of time during the switching period [1]. Other types of cycles which have also been used are stress [2], and temperature [3]. In order to carry out these types of experiments, a new capability has been added to The Australian Stress Scanner (TASS) instrument [4] at the High Flux Australian Reactor (HIFAR) operated by the Australian Nuclear Science and Technology Organisation (ANSTO). TASS is the former Triple Axis Spectrometer which, within the last couple of years, has been significantly refurbished (including the introduction of a multi-line, position-sensitive detector) to function as a two-axis diffractometer for strain mapping in engineering materials. This capability will allow for such stroboscopic experiments to be performed using the switching of high-voltage electric fields. The exact operation of the device is outlined in the experimental details section below. The common ferroelectric material, triglycine sulphate, will be used as a model crystal for the commissioning of the stroboscopic technique at HIFAR since, in a previous study involving stroboscopic diffraction intensity measurements at the ISIS [5], most unusual time dependencies for diffraction peak intensities from a TGS crystal in response to the switching of high-voltage electric fields applied to the crystal were observed.
URI: https://www.physics.org.au/wp-content/uploads/cmm/2005/05._Daniels_AIP2005_CMMSP.pdf
https://apo.ansto.gov.au/dspace/handle/10238/11663
ISBN: 0-9598064-8-2
Appears in Collections:Conference Publications

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