Dr. M. Charles Robert, Associate professor
PG Department of Physics, HKRH College, Uthamapalayam
Ph. D. topic:
Structural and Physical Characterization of thermoelectric materials
Date of Regis: 15.12.2005 Reg. No. 3521 Viva-Voce date: 08.08.2014
Introduction about the Ph.D. work:
Knowing something impossible can be made visually by naked eyes is of great interest and informative. The pictorial representation of the internal structure of a solid will be highly useful for the proper selection of the technologically important materials such as thermoelectric materials for the device applications. The selected thermoelectric materials for the study of the electron level properties, were (1) magnesium silicide (Mg2Si) (2) lead telluride (PbTe) (3) bismuth doped with antimony Bi1-xSbx (4) bismuth telluride (Bi2Te3) (5) antimony telluride (Sb2Te3) (6) tin telluride doped with germanium (single crystals) Sn1-xGexTe and (7) indium antimonide single crystals (InSb). The core of the research work completed includes the following.
- Recording of high quality X-ray diffraction data both in powder form as well as single crystal form.
- The study of the average structure of the materials using the least square fitting by Rietveld technique using the software JANA 2006.
- The charge density distribution analysis using the versatile technique maximum entropy method (MEM).
- The visualization of the electronic charge distribution in three, two and one dimension. The extraction of the electron level properties both qualitatively and quantitatively.
- The local structure analysis of the materials using atomic correlation function called pair distribution function (PDF) for the powder samples
List of publications:
- Local structure of the thermoelectric material Mg2Si using XRD, R. Saravanan and M. Charles Robert, Journal of alloys and compounds (ELSEVIER), 479 (2009), p.26-31, Impact factor – 2.39, No. of citations – 32
- Local structure of high temperature thermoelectric material PbTe using the maximum entropy method 9MEM) and pair distribution function (PDF), R. Saravanan and M. Charles Robert, Journal of physics and Chemistry of solids (ELSEVIER), 70 (2009), p.159-163, Impact factor – 1.517, No. of citations – 7
- Triple phase structure and electron density analysis of the thermoelectric material Bi80Sb20, Charles Robert and R. Saravanan, Powder Technology (ELSEVIER), 197 (2010) p.159-164, Impact factor – 2.265, No. of citations – 8
- Experimental electronic structure of the thermoelectric materials Bi2Te3 and Sb2Te3, T. Akilan, M. Charles Robert and R. Saravanan, Materials science forum, Trans Tech publications, 699 (2012) p.103-121. Impact factor – 0.56
- Single crystal X-ray analysis of the electronic structure of the thermoelectric material Sn1-xGexTe, M. Charles Robert and R. Saravanan, Indian Journal of physics, 84(9) (2010), p.1203-1210, Impact factor – 0.381, No. of citations – 1
- Single crystal charge density studies of the thermoelectric material Indium Antimonide, Charles Robert, B. Subha and R. Saravanan, Z.Natureforsch, 66a (2011), p.562-568, Impact factor – 1.363, No. of citations – 1
- Structural analysis of Al, Ni and Cu using the maximum entropy method, multipole and pair distribution function, M. Charles Robert, R. Saravanan, K. Saravanakumar and M. Prema R Natureforsch, 64a (2009) p.361-369, Impact factor – 0.8
- Structural, optical and magnetic properties of Ga2-xFexO3, M. Charles Robert, S. Sasikumar, S. Saravanakumar and R. Saravanan, Materials Research Forum, 7 (2017) p.21-30
- Preparation, electronic structure and chemical bonding of lead free (1-x)(K0.5Bi0.5)TiO3-xBaTiO3 solid solution, S. Sasikumar, R. Saravanan, S. Saravanakumar and M. Charles Robert, Applied Physics A, Materials Science and Processing, (2018), p.124-131, Impact factor –1.694