Research Outcome – Dr. Rita John

Area of Research

Theoretical, Computational and Experimental Condensed Matter Physics

Density Functional Theory based calculations
Band Gap Engineering in binary, ternary and quaternary semiconductors
Quantum Confinements in Nano Materials
Smart Materials for Bio Medical and Space Applications.
2D materials
Topological insulators
Spintronics
Topological Weyl and Dirac semimetals
Topological phases in terms of crystal symmetries
Novel Thermoelectric materials using Density Functional Theory methods and machine learning algorithms

Our Research Outcome

Electronic structure of ternary half-Heusler ZrIrBi alloy

Half Heusler (HH) alloys are significant as they provide a new platform for exploring topologically nontrivial state. The nature of electronic structure of ternary half-Heusler ZrIrBi alloy change when spin-orbit coupling is included.

Band structures of ZrIrBi without (left) and with (right) Spin Orbit coupling

Research Guidance

Degree Completed

Ph.D : 8

M.Phil : 40

M.Sc over 75 and

M.Tech : 2

Ongoing

7 Research Scholars

Band Structure of TiPd (b) Brillouin Zone of a cubic crystal with high symmetry k-points (c ) Fermi surface of TiPd due to band 14 and (d) Fermisurface of TiPd

Reference: International Journal for Research in Applied Science & Engineering Technology (IJRASET), Volume 6 Issue III, March, 2018.

Variation in zero frequency limit of dielectric constant e1(0) refractive index n(0) and reflectivity R (0) as a function of concentration x in Zn1-xA S (A=Cr/Mn/Fe ; x=0.25,0.50,0.75)

Reference: Materials Science and Engineering: B, B 248, 114401 2019

2D materials : Structure and properties

Graphene, silicene, germanene, and stanene were investigated due to their excellent electronic and optical properties. Their stability and bonding characteristics were studied using single point energy calculations. The sp² to sp³ hybridization in materials other than graphene causes puckering.

2D Materials: Dirac cone and zero density of states

The electronic band structure, density of states (DOS), and charge density contours were explored. The Dirac cone and zero density of states were observed in all materials at Fermi level.

2D materials: Optical properties

The optical properties across different planes in the entire optical region from infrared to far ultraviolet were analyzed to find their suitability in optical applications. The plasma frequency was observed in all materials other than graphene.

Dirac Cone

Plasma frequency

Birefringence characteristics exhibited by all 2D materials

(a) Graphene

(b) Silicene

(c) Germanene

(d) Stanene

Reference: Journal of Superconductivity and Novel Magnetism, 32 (4), 977-986, 2018.

Density of d-states at Fermi level, EF for (a) Ti43.75Pd50X6.25 and (b) Ti50Pd43.75X6.25. In Fig.(a), Ti1, Ti2, and Ti3 represent the three nonequivalent Ti atoms in the Ti43.75Pd50X6.25 series and in Fig.(b), Pd1, Pd2, and Pd3 represent the three nonequivalent Pd atoms in Ti50Pd43.75X6.25 series.

Reference: International Journal for Research in Applied Science and Engineering Technology, Vol. 6, Issue III, 2018

Zn+Mg co-doped TiO2 for Dye Sensitized Solar Cell (DSSC) application

Band Gap Engineering

Reference:

International Journal of Materials, Mechanics and Manufacturing, Vol. 8, No. 1, 2020.
Chalcogenide Letters 7 (4), 263-268, 2010
Advanced Materials Research 31, 164-166, 2008.
Computational materials science 44 (1), 106-110, 2008
Solid State Phenomena 124, 57, 2007
Physica Status Solidi-B-Basic Research 226 (2), 375-384, 2001.

Dr. Rita John