EPSRC Reference: |
GR/R00500/01 |
Title: |
Optimisation of Thermistor Performance Through Local Property Analysis |
Principal Investigator: |
Leach, Dr C |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Materials |
Organisation: |
University of Manchester, The |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
01 April 2001 |
Ends: |
31 December 2004 |
Value (£): |
218,014
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EPSRC Research Topic Classifications: |
Electronic Devices & Subsys. |
Materials Characterisation |
Materials Processing |
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EPSRC Industrial Sector Classifications: |
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Related Grants: |
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Panel History: |
Panel Date | Panel Name | Outcome |
20 Jul 2000
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Electronics/Electronic Materials Panel
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Deferred
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Summary on Grant Application Form |
We wish to study the electrical structure of individual grain boundaries in PTC thermistors, using SEM based hot stage conductive mode microscopy techniques complemented by the development of localised AC impedance and low temperature conductivity measurements. This will be correlated with detailed crystallographic and compositional studies of the interfaces and used to address issues concerned with the processing and application of positive temperature coefficient (PTC) thermistors, such as in-service failure and minimisation of the pellet resistance below the Curie temperature.We propose to extend the model for the behaviour of thermistor grain boundaries, taking into account terms specific to individual interfaces, including the form of the PTC curve, segregation of dopants, alloying elements and impurities, grain boundary structure (misorientation and plane), local crystallographic effects including domain texture, trap levels, capacitance and dielectric constant variations as a function of temperature. The overall performance of commercial thermistors, particularly during the transient heating phase, along with stresses induced by thermal, piezo- and domain effects, will be modelled by finite element techniques. We will do this by considering the performance of individual grain boundary structures and small networks of interfaces, and integrating these data over the whole device.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.man.ac.uk |