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DST Seminar: Engineering at the Nanoscale – gaining insight through advanced characterisation

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Prof Barbara Shollock
WMG, University of Warwick
1:30-2:30pm
Wednesday 5th December
Materials & Analytical Sciences 2.06

From the gas turbines that power the Airbus to the steels used for cars and food cans, engineering alloys form an important class of materials, but can appear less exciting than headline-grabbing nanomaterials and biomaterials.

Despite their unglamorous press, these alloys require understanding at the nanoscale to develop new alloys and to mitigate failure in service. This talk will review a range of alloys, the challenges they face in service and characterisation approaches to determine their nanoscale chemical, structural and physical behaviour.

Tue 04 December 2018, 11:11 | Tags: Seminar

DST Seminar: Fancy Colored Diamonds: Towards an Understanding of their Color Origin

Ulrika D'Haenens-Johansson
Gemological Institute of America (GIA), New York, USA
1pm - 2pm, Monday 3rd December
Materials & Analytical Sciences (MAS 2.06)

Traditionally, when people think of diamonds as a gemstone they visualize the classic colorless round brilliant. However, through the incorporation of point or extended defects in the crystal lattice, the full rainbow of colors can be found in natural diamonds. These rare diamonds, termed “Fancy Colored” in the gem trade, often command higher per carat* prices (up to $3.3 million per carat) compared to their colorless counterparts, generating great excitement at auctions and in the news. These colors can also be produced artificially through treatment of selected natural or laboratory-grown diamonds. By studying the structure, formation and destruction of color producing defects in diamond through a range of spectroscopic techniques it is possible to separate natural, treated and synthetic diamonds, maintaining transparency in the trade. In this seminar we will review some of the key color-producing defects in both natural and synthetic diamonds and see examples of how careful defect engineering can be used to produce attractive fancy colored materials.
*1 carat = 200 mg

Mon 26 November 2018, 15:15 | Tags: Seminar

DST Seminar: Nitrogen aggregation in diamond - Matthew Dale, De Beers Technologies

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1-2pm Monday 26th November
Materials & Analytical Sciences 2.06

Nitrogen is the most commonly identified impurity in diamond. When diamond is annealed with sufficient temperature, various species become mobile and single nitrogen substitutional atoms aggregate into larger complexes. Understanding and controlling this process is significant to engineering defects into diamond, such as the nitrogen-vacancy centre, as well as understanding the differences between natural and synthetic diamond. Irradiation prior to annealing increases the aggregation rate; this is caused by both vacancies and interstitials mediating the mobility of nitrogen. In this presentation I will talk about the migration of vacancies and interstitials and their role in enhancing the aggregation process. I will highlight differences between aggregation in natural, HPHT and CVD grown diamond. Finally, I will explain how these differences can be used to effectively distinguish natural from synthetic diamond and their use in De Beers’ screening instruments.

Tue 20 November 2018, 12:35 | Tags: Seminar

DST Seminar: Story of a Puzzle: Another Facet of Diamond - Gwenaelle Lefeuvre, Micronsemiconductor Ltd

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2pm - 3pm, Wednesday 21st November
Materials & Analytical Sciences (MAS 2.06)

Although its optical properties are those most often cited and even revered, diamond also possesses characteristics that extend its field of application well beyond luxury jewellery.

This presentation focuses in particular on the electronic properties of diamonds, thanks to which Micron Semiconductor manufactures radiation sensors for applications as diverse as particle physics, space exploration, energy or medical diagnostics.

After an introduction on artificial diamond and its various uses, we will explore the steps involved in manufacturing a sensor and examine current and future applications in this sector.

Mon 12 November 2018, 16:10 | Tags: Seminar

DST CDT at the 2018 GIA Symposium

Gloria Zhao (Cohort 3) and Phil Diggle (Cohort 1), along with Prof. Mark Newton, were invited to attend the 2018 Gemological Institute of America (GIA) International Gemological Symposium. Phil delivered a talk on how to image diamond down the diffraction limit using confocal photoluminescence microscopy and how this has revealed new insights on the growth of synthetic diamond. Gloria gave a talk on phosphorescence and thermoluminescence of diamond. Both talks were very well received by the 200-plus audience members in the morning session of the first day of the symposium. The remainder of the first day saw talks from leading researchers in their field of diamond science from the synthesis, characterisation and the geology of diamond.

Mon 29 October 2018, 11:09 | Tags: StudentNews

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