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High pyroelectric sensitivity in alternate layer Langmuir-Blodgett superlattices

Lacey, D., Holder, Simon J., Majid, W.H.A., Capan, R., Richardson, T. (1995) High pyroelectric sensitivity in alternate layer Langmuir-Blodgett superlattices. Materials Science and Engineering: C, 3 (3-4). pp. 197-203. ISSN 0928-4931. (doi:10.1016/0928-4931(95)00070-4) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:36822)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL
http://dx.doi.org/10.1016/0928-4931(95)00070-4

Abstract

A family of polysiloxanes which have been designed for the purpose of achieving high pyroelectric activity in Langmuir-Blodgett (LB) film form is reported. The alternate layer LB deposition process has been used in which each siloxane monolayer (S) is co-deposited with a monomeric eicosylamine monolayer (E) to form alternate layer multilayer assemblies of the form SESESE… This approach ensures a macroscopic polarization within the LB film, which is an essential criterion for observation of the pyroelectric effect. Pyroelectric devices have been fabricated using aluminium electrodes and their pyroelectric sensitivity has been measured using a quasi-static technique. This collaborative study has involved investigating the effect on the pyroelectric response of (i) varying the degree of substitution on the polysiloxane backbone with aliphatic pendant side-chains, (ii) varying the length of the aliphatic pendant side-chains and (iii) incorporating polar aromatic pendant side-chains. This iterative strategy has led to an improvement in the pyroelectric coefficient from around 0.8 ?C m?2 K?1 for an aliphatic substituted homopolymer to 4.6 ?C m?2 K?1 for a copolysiloxane substituted with an aromatic pendant side-chain. The effects of LB film thickness (number of deposited monolayers) and the electrode overlap area have also been investigated and have brought about a further dramatic increase in activity to around 13 ?C m?2 K?1. This is the highest pyroelectric coefficient ever reported for an alternate layer LB film assembly. It is believed that the activity of these thin films arises predominantly from the primary pyroelectric effect since an investigation into the response from two substrates possessing very different thermal expansion coefficients yielded almost identical behaviour, suggesting that the secondary piezoelectric component is small.

Item Type: Article
DOI/Identification number: 10.1016/0928-4931(95)00070-4
Uncontrolled keywords: Pyroelectric sensitivity; Langmuir-Blodgett superlattices; Polysiloxanes
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Simon Holder
Date Deposited: 22 Nov 2013 16:34 UTC
Last Modified: 16 Nov 2021 10:13 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/36822 (The current URI for this page, for reference purposes)
Holder, Simon J.: https://orcid.org/0000-0001-8977-9257
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