[Academic] Fwd: SUPAMAIL: Colloquium on Friday 5th July, 2013 (reminder)

[Maxim Fedorov]

Dear Colleagues,

This is just a gentle reminder about the seminar today at 11 am in JA 5.05.

High throughput search for better nanograined thermoelectrics

J. Carrete


The abstract is below.

Many thanks.

Regards,

Maxim

Maxim V. Fedorov, PhD, DSc
----------------------------------------
Professor in Physics and Life Sciences
----------------------------------------
Director, ARCHIE-WeST
West of Scotland Academia-Industry Supercomputing Centre
(www.archie-west.ac.uk<http://www.archie-west.ac.uk>)
----------------------------------------
Nanoscience Division
Department of Physics
Scottish Universities Physics Alliance (SUPA)
Strathclyde University
John Anderson Building
107 Rottenrow East
Glasgow, U.K.
G4 0NG

tel: +44 (0)141-5484012
fax: +44 (0)141-5522891
e-mail: maxim.fedorov at strath.ac.uk<mailto:maxim.fedorov at strath.ac.uk>

Begin forwarded message:

From: Yen-Fu Chen <yen-fu.chen at supa.ac.uk<mailto:yen-fu.chen at supa.ac.uk>>
Subject: SUPAMAIL: Colloquium on Friday 5th July, 2013
Date: 3 July 2013 13:54:58 GMT+01:00
To: Maxim Fedorov <maxim.fedorov at strath.ac.uk<mailto:maxim.fedorov at strath.ac.uk>>

SUPAMAIL<http://my.supa.ac.uk/course/view.php?id=116> » Forums<http://my.supa.ac.uk/mod/forum/index.php?id=116> » News forum<http://my.supa.ac.uk/mod/forum/view.php?f=294> » Colloquium on Friday 5th July, 2013<http://my.supa.ac.uk/mod/forum/discuss.php?d=2700>
[http://my.supa.ac.uk/theme/SUPA4/pix/u/f2.png]<http://my.supa.ac.uk/user/view.php?id=2280&course=116>
Colloquium on Friday 5th July, 2013
by Yen-Fu Chen<http://my.supa.ac.uk/user/view.php?id=2280&course=116> - Wednesday, 3 July 2013, 01:48 PM


11pm on Friday 5th July in Room 5.05 of the John Anderson Building, Strathclyde University
All are welcome to attend a colloquium on this Friday at Strathclyde University:
J. Carrete of CEA-Grenoble will speak on “High throughput search for better nanograined thermoelectrics”
________________________________
Abstract
High throughput search for better nanograined thermoelectrics
J. Carrete
jesus.carretemontana at cea.fr<mailto:jesus.carretemontana at cea.fr>
CEA-Grenoble, 17 Rue des Martyrs, Grenoble 38000, France
The viability of thermoelectric energy conversion as an alternative to more traditional technologies depends on the availability of materials with a high thermoelectric figure of merit (ZT). Such materials would be characterized by low thermal conductivities and high electrical conductivities and Seebeck coefficients. The intricacy of this materials optimization problem caused a stagnation of the field for several decades until the advent of modern, powerful nanostructuring techniques. Among them, the synthesis of nanograined materials has several advantages, such as relying only on intrinsic properties and being able to produce bulk samples directly. Still, experimental resources are scarce and so far researchers have focused their efforts on improving known compounds with high bulk ZT, or alternatively on cheap and readily available materials like silicon.
                This presentation is devoted to the results of a fully ab-initio high-throughput screening of a large library of nanograined thermoelectrics. All the phenomenological coefficients involved in ZT were directly calculated for each material without experimental input. The first class explored comprised the 78,768 ternary compounds with half-Heusler prototype available in theaflowlib.org<http://aflowlib.org> repository. Comparison shows that many half-Heusler candidates can have higher performance than those from elementary group-IV and binary III-V semiconductors. More specifically, values of ZT near 3 are plausible at high temperatures. Good candidates can be found for use either as type-p or as type-n thermoelectrics.
                The factors underlying the advantages of half Heuslers in this context are analyzed, and the distribution of ZT over this class of materials studied in terms of their constituent elements, leading to practical recipes that can help guide experimental studies. For instance, good candidates are more likely to appear if two of their elements come from the first columns of the periodic table. Comparison with experimental data for several well-known half Heuslers shows that thermoelectric performance in the bulk and in nanograined form do not necessarily go hand in hand, underlining the importance of looking for the right material for each regime.
                In order to go beyond nanograined structures, a software tool chain is presented that implements lattice thermal conductivity calculations for semiconductors in bulk and nanowire forms. At its core is a solver for the Boltzmann transport equation based on ab-initio input. Using the same library of half Heusler as test systems, the difficulties of a brute-force high-throughput approach to this problem are discussed, and an alternative based on machine-learning techniques is introduced.
See this post in context<http://my.supa.ac.uk/mod/forum/discuss.php?d=2700#p3079>