[institut] Reminder: SCL seminar: Ivana Savic, today, 14:00

[Nenad Vukmirovic]

Dear colleagues,

You are cordially invited to the Scientific Computing Laboratory 
seminar, which will be held on Thursday 21 April 2016 at 14:00 in the 
library reading room "Dr Dragan Popovic" of the Institute of Physics 
Belgrade. The talk entitled

Understanding and Manipulating Lattice Instability of PbTe for Improved 
Thermoelectric Performance

will be given by Dr Ivana Savic (Tyndall National Institute, Cork, 
Ireland). Abstract of the talk:

Thermoelectric materials could play an important role in energy 
harvesting and solid state cooling applications since they enable 
conversion between thermal and electrical energy [1]. The key physical 
properties for good thermoelectric performance are high electrical 
conductivity, high Seebeck coefficient and low thermal conductivity [1]. 
In many materials the improvement of one of these characteristics leads 
to a disimprovement of others, and the optimization of the overall 
thermoelectric performance is highly challenging.

It has been recently proposed that the proximity to a structural phase 
transition of PbTe is one of the key factors leading to its low thermal 
conductivity and high thermoelectric efficiency [2]. In this talk, using 
first principles calculations, I will show that driving PbTe closer to 
the structural phase transition via strain or alloying could 
substantially suppress its thermal conductivity [3]. Furthermore, using 
a combination of ultrafast X-ray scattering measurements and first 
principles calculations, I will show that the coupling of the electronic 
states near the band edges to transverse optical phonons drives PbTe 
near the structural instability [4]. These insights may open new 
opportunities for the development of more efficient thermoelectric 
materials.

[1] G. J. Snyder and E. S. Toberer, Nat. Mater. 7, 105 (2008).
[2] O. Delaire et al., Nat. Mater. 10, 614 (2011).
[3] R. M. Murphy, E. D. Murray, S. Fahy, and I. Savic, Phys. Rev. B 93, 
104304 (2016)
[4] M. P. Jiang, M. Trigo, I. Savic et al., submitted.

Best regards,

-- 
Dr Nenad Vukmirovic,
Associate Research Professor,
Scientific Computing Laboratory,
Institute of Physics Belgrade,
Serbia.
URL: http://www.scl.rs/nenad