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Details of Grant 

EPSRC Reference: GR/J29763/01
Title: PHONON SCATTERING FROM MULTILAYERED DISSIPATIVE STRUCTURES
Principal Investigator: Wigmore, Professor JK
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department: Physics
Organisation: Lancaster University
Scheme: Standard Research (Pre-FEC)
Starts: 22 January 1994 Ends: 21 January 1995 Value (£): 46,985
EPSRC Research Topic Classifications:
Condensed Matter Physics
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:  
Summary on Grant Application Form
We are re-applying for funds to support a Visiting Fellow to work in collaboration both with Dr J K Wigmore at Lancaster, and also with Dr V W Rampton at Nottingham. The proposal has been significantly re-written to sharpen its focus on the important points. The reason for this arrangement is that Dr Kozorezov would be working to construct a new general model of phonon scattering from multilayered dissipative structures that would be strongly relevant to current research at both universities. Broadly, the division of interest is between incoherent phonon investigations at Lancaster, involving nanosecond phonon pulse experiments, and coherent work at Nottingham using bulk and surface acoustic waves. At Lancaster we are carrying out several investigations using nanosecond heat pulse techniques to study the interaction of phonons with defects and carriers at interfaces and in layer structures. We have recently completed a study of the effect of ion bombardment on silicon wafers. Strong phonon scattering arises from the resulting amorphous layer and this type of scattering can be distinguished experimentally from that due to the irregularity of the interfaces. In a further proposal we aim to extend this work to studies of the pseudomorphic Si-Ge layer structures in collaboration with Kyushu Institute of Technology, Japan. We are also studying the electron-phonon interaction of the two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure by observing directly the phonons emitted and absorbed by the 2DEG. Although the dissipative 2DEG is totally different from the amorphous layer, the basic model of the process is essentially the same. The transfer matrix formalism describing the scattering between layers can be processed separately from the dynamic response function describing the dissipation in a particular layer. The experiments at Nottingham are coherent, involving the study of the 2DEG in GaAs/AlGaAs and silicon MOSFET structures by bulk and surface acoustic waves. But again the basic theoretical model is the same as described above, and only the detailed experimental interpretation is different. Dr Kozorezov's background makes him particularly well suited to undertaking this exciting project, and he has already collaborated on a smaller scale with JKW and VWR. It is the intention that although he will be based in Lancaster, his time will be divided more or less equally between the two projects, coherent and incoherent.
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Organisation Website: http://www.lancs.ac.uk