Dr.Raj Kumar Khan

Dr.Raj Kumar Khan

Designation:

Assistant Professor

Specialization:

Soft Condensed Matter Physics, Liquid Crystal.

Email:

raj.khan@thapar.edu

Academics:

  • 2010, BSc in Physics (Hons.), The University of Burdwan, India.
  • 2012, MSc in Physics, Visva Bharati, Santiniketan, India.
  • 2019, Ph.D. in Physics (Experimental), The University of Calcutta, India.

Work experience:

  • August 2014 - August 2016: Junior research fellow: Department of Physics, University of Calcutta, Kolkata, India.
  • August 2016 - Dec 2018: Senior research fellow: Department of Physics, University of Calcutta, Kolkata, India.
  • April 2019 – September 2022: Post-doctoral Fellow (Research Associate), Raman Research Institute, Bengaluru, India.
  • September 2022 – present: Assistant Professor, School of Physics and Material Science, Thapar Institute of Engineering and Technology, Patiala, Punjab, India.

Research interest:

  • Blue phase liquid crystals: development and thermal stabilization by nanoparticles and electro-optic effects.
  • Visco-elastic, dielectric and electro-optical properties of nematic and smectic liquid crystals made of bent-core molecules.
  • Impact of nanoscale particles on electro-optical properties of nematic liquid crystals.
  • Dielectric spectroscopy and electro-optical studies of high-tilt antiferroelectric liquid crystals and Ferro- and antiferroelectric liquid crystals in planar geometry doped with nanomaterials.
  • Stretchability and Rheological study of thermotropic and lyotropic liquid crystal physical gel.

Fellowship and awards:

  • Qualified Graduate Aptitude Test of Engineers (GATE, a national-level test in India) in 2014.
  • Qualified National Eligibility Test (NET, Council of Scientific & Industrial Research – Univ. Grants Commission, Govt. of India.) in 2012 and 2015.
  • Best Poster Award at National Conference on Liquid Crystals (NCLC-2016) December 07-09, 2016, ISM, Dhanbad, India.

Publications:

  1. Novel achiral four-ring bent-shaped nematic liquid crystals with trifluoromethyl and methyl substituents in the central molecular core: an unusually large Kerr constant in blue phase III of nematic-chiral dopant mixture; R. K. Khan, S. Turlapati, N. V. S. Rao, R. Pratibha, W. Drzewinski, R. Dabrowski and S. Ghosh, Journal of Materials Chemistry C, 5 (2017): 6729. DOI: 10.1039/c7tc01186e.
  2. Impact of terminal polar substitution on elastic, electro-optic, and dielectric properties of four-ring bent-core nematic liquid crystal; K. Khan, S. Ghosh, S. Turlapati, N. V. S. Rao, RSC Advances, 8 (2018): 11509. DOI: 10.1039/C8RA00575C.
  3. Sign-inversion of elastic anisotropy in a bent-core nematic liquid crystal doped with carbon nanodots; K. Khan, S. Turlapati, N. V. S. Rao and S. Ghosh, Journal of Molecular Liquids, 225 (2017): 328. DOI: 10.1016/j.molliq.2016.11.075.
  4. Elastic and dielectric properties of ferroelectric nanoparticles/bent-core nematic liquid crystal blend; R. K. Khan, S. Ghosh, S. Turlapati and N. V. S. Rao, The European Physical Journal E, 40 (2017): 75. DOI: 10.1140/epje/i2017-11564-x.
  5. Elastic constants, viscosity and dielectric properties of bent-core nematic liquid crystals doped with single-walled carbon nanotubes; S. Turlapati, R. K. Khan, P. R. Ramesh, J. Shamanna, S. Ghosh and N. V. S. Rao, Liquid Crystals, 44 (2017): 784. DOI: 10.1080/02678292.2016.1242177.
  6. Existence of polar switching in the nematic and orthogonal smectic phases in novel four-ring bent-core compounds; S. Turlapati, R. K. Khan, S. Ghosh, P. Tadapatri, R. Pratibha and N. V. S. Rao, Journal of Applied Physics, 120 (2016): 174101. DOI: 10.1063/1.4966936.
  7. Observation of disordered mesophase in three-ring based highly polar bent-core molecules; G. Mohiuddin, N. Begum, N. V. S. Rao, V. Punjani, S. Kaur, S. K. Pal, R. K. Khan and S. Ghosh, Liquid Crystals, 44 (2017): 2247. DOI: 10.1080/02678292 .2017.1363917.
  8. Observation of polar order and thermochromic behaviour in a chiral bent-core system exhibiting exotic mesophases by superstructural frustration; V. Punjani, G. Mohiuddin, S. Kaur, R. K. Khan, S. Ghosh and S. Pal, Chemical Communications, (2018) DOI:  10.1039/C7CC08885J.
  9. Polar Switching and Cybotactic Nematic Ordering in 1,3,4-Thiadiazole-Based Short-Core Hockey Stick-Shaped Fluorescent Liquid Crystals; S. K. Saha, G. Mohiuddin, M. K. Paul, S. P. Gupta, R. K. Khan, S. Ghosh and S. K. Pal, ACS Omega, 4 (2019): 7711. DOI: 10.1021/acsomega.9b00425.
  10. Structural organization and molecular self-assembly of a new class of polar and non-polar four-ring based bent-core molecules, S. Kaur, G. Mohiuddin, V. Punjani, R. K.  Khan, S. Ghosh, S. K. Pal, Journal of Molecular Liquids, 295 (2019): 111687. DOI: 10.1016/j.molliq.2019.111687.
  11. Development of nematic and orthogonal smectic phases in short-core fluorinated hockey-stick shaped liquid crystal compounds, K. Upadhyaya, S. Ghosh, R. K. Khan, R. Pratibha and N. V. S. Rao, Journal of Molecular Liquids, 298 (2020): 111989. DOI: 10.1016/j.molliq.2019.111989.
  12. Electrochemical performance of a new imidazolium ionic liquid crystal and carbon paste composite electrode for the sensitive detection of paracetamol, R. Mangaiyarkarasi, S. Premlatha, Raj Kumar Khan, R. Pratibha and S. Umadevi, Journal of Molecular Liquids, 319 (2020): 114255. DOI: 10.1016/j.molliq.2020. 114255.
  13. Selective stabilization of blue phase liquid crystals using spherical and rod-shaped colloidal nanocrystals, Raj Kumar Khan and Pratibha Ramarao, Journal of Applied Physics, 129, 024702 (2021); DOI: 10.1063/5.0035810.
  14. Planar and Vertical Alignment of Rod-like and Bent-core Liquid Crystals Using Functionalized Indium Tin Oxide Substrates, B. Sivaranjini, S. Umadevi, Raj Kumar Khan, R. Pratibha, D. Amuthan, V. Saranyan, and V.Ganesh. Liquid Crystals, (2021) 1; doi.org/10.1080/02678292.2021.1995061.
  15. Interplay of self-assembly and viscoelasticity in chiral liquid crystal gels, Raj Kumar Khan, Sayantan Majumdar and R. Pratibha. Physics of Fluids, 34, 047108 (2022); doi.org/10.1063/5.0086129.
  16. Extremely High Kerr Constant and Low Operating Voltage in a Stable Room-Temperature Blue Phase-III Derived from Three-Ring-Based Bent-Core Molecules, Raj Kumar Khan, Golam Mohiuddin, Nazma Begum, Srikanth Turlapati, Rao V. S. Nandiraju, Bugra Koknarugmani Debbarma, and Sharmistha Ghosh. ACS Applied Materials & Interfaces, 14 (2022), 42628, https://doi.org/10.1021/acsami.2c09392.   
  17. Dielectric and Elastic Properties of Pure and Semiconducting CdS Quantum Dots Dispersed Four Ring Fluorinated Bent-Core Nematic Liquid Crystal, Raj Kumar Khan, Subhadra Mohapatra, and Sharmistha Ghosh. Molecular Crystals and Liquid Crystals, (2023), https://doi.org/10.1080/15421406.2023.2210949.

Papers Presented at Conferences:

  • Effect of carbon nanotubes on dielectric permittivity and elastic constants of a bent-core nematic liquid crystal, K. Khan, S. Turlapati, N. V. S. Rao and S. Ghosh, Condensed Matter Days 2015 (August 27-29, 2015), Visva-Bharati, Santiniketan, India.
  • Superior visco-elastic and ionic activities with reversal of elastic anisotropy observed in bent-core nematic liquid crystals doped with carbon nanotubes, Raj Kumar Khan, Sharmistha Ghosh, Nandiraju V. S. Rao, National Conference on Liquid Crystals (NCLC-2016) December 07-09, 2016, ISM, Dhanbad, India.
  • Electro-optical study of blue phase III derived from four-ring bent-core liquid crystal exhibiting large Kerr coefficient, Raj Kumar Khan, Srikanth Turlapati, Nandiraju V.S. Rao and Sharmistha Ghosh, National Conference on Liquid Crystals (NCLC-2017) October 11-13, 2017, IISER Mohali, Chandigarh, India.
  • Stable electro-optic Kerr response in wide-temperature blue phase III realised with a four-ring bent-core liquid crystal, Raj Kumar Khan, Sharmistha Ghosh, and R. Pratibha, CompFlu 2019, December 5 – 7, 2019, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal, India.
  • Stabilization of Blue Phase by CdSe-Cds Quantum Nano Rod: Measurement of Kerr Constant, Raj Kumar Khan, International conference on Advancement in Core and Frontier of Physics, February 05−07, 2022, Department of Physics, GLA University, Mathura, India