Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.774909
Title: Characterisation and preparation of superconducting diamond films for the production of nems and squids
Author: Werrell, Jessica
ISNI:       0000 0004 7962 1095
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2018
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Abstract:
Boron doped nanocrystalline diamond has intrinsic properties (namely a high young's modulus to density ratio) that make it an appealing material for the construction of nano-electro-mechanical systems and superconducting quantum interference devices; which can then be used to investigate macroscopic quantum states. This thesis seeks to characterize the superconducting properties of films of this material, as measured by AC susceptibility and magnetic relaxation, in preparation for its use in the aforementioned fabrications. The properties under investigation using the AC susceptibility are the superconducting volume fraction of the sample, its critical temperature and critical current density. This thesis investigates how these properties change for diamond films grown to different thicknesses, 160 - 564 nm. It is shown that all films consist of a hundred percent superconducting material; although these typical volume fraction calculations simplify the results such that details of the transition are lost. The critical temperature is shown to be in close agreement with a critical temperature calculated considering fluctuating conduction behaviour from resistivity measurements. This thesis also gives further evidence for the recently discovered superconducting glass state within diamonds phase diagram. A pinning potential is also calculated for the thickest diamond sample in the set; which is a factor of 2 smaller than the only published value of diamond available. This difference is likely due to the growth and measurement set up variations. Finally this thesis shows how simple improvements can be made the chemical mechanical polishing of this material, which will ultimately improve device performance.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.774909  DOI: Not available
Keywords: QC Physics
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