When scientists synthesize with a dream of discovering a new material, in most cases it is a drive of curiosity that propells science. However, targeted drives often considers realistic possibilities and sometimes are based on emotions. History of exotic materials have often been accidental and sometimes unintentional but we must always remember that the follow up has been realistic and targeted towards improvement in the same functionality.
One question arises always. Is mother Earth or the Universe naturally deprived of such exotic materials or is it just that we have never known these materials because we did not find them. The answers to these questions may never be found if we do not find these materials one day by exploration. However, to create these materials is not easy.
Materials even if they have the same chemical composition may differ in phase which means structure or some physical property. This is because during synthesis the environment dominates the kinetics of the molecules and hence the formation of a phase takes place with a definite functionality. It is absolutely difficult to reproduce the exact same environment between two synthesis but most materials have a steady domain of conditions where a prefered phase is maintained. But this is not a guaranteed effect for sensitive compositions, especially in the nano regime where surface energy of the materials drive a dominant role in formation. Hence, often we find contradictory results from the same material synthesized via a slightly different route.
Let us get to the scale of the atoms and imagine that they are like social bodies trying to arrange themselves in a social pattern. Depending on the prevailing boundaries of given conditions these bodies will try to arrange themselves according to their intellect which in the case of the atom may be the instantaneous energy distribution in the atom. This distribution if made uniform by quasi-statically approaching some kinetic equilibrium state. Then only the molecules get the chance of behaving exactly in the same way.
In the social analogy it is equivalent to a social order where there is one social form being formed by gradually introducing discipline in the frame and bringing in more and more people in the same format. This is the phenomenon of crystallization of a solid when you achieve a regular structure over a large form of matter. On the other hand the glassy or amorphous phase is a frozen liquid or disturbed/perturbed state of the same composition which does not have a long range structure or has a continuously modifying arrangement of atoms comparable to societies with less law and order.
The SMART group targets to study these social behaviours in the molecular level of matter where the units are subject to various defined social pressure and extract the functionality of that certain perturbed state of matter.
RESEARCH FOCUS:
Magnetism, Multiferroics, Spintronics, Semiconductors Materials: Nanocrystals, Microcrystals, Thin films, Single Crystals, Glasses
Synthesis, Structural/electronic/magnetic characterization to investigate multiferroicity in perovskite oxides; Superconductivity in TM-intercalated Pnictogen Chalcogenide Topological Insulators and other oxides; Spintronics in dilute magnetic semiconductors Photoconduction properties of transition metal doped ZnO for device applications; Negative photoconduction in random ZnO/carbon nanotube network; Self-assembled nanofabrication and characterization for semiconductors and oxide materials (nanopartciles, nanowires) for nanodevice applications; Synthesis, structural and photoelectric / electronic properties of semiconductors
CHARACTERISATION TECHNIQUES used in analysis:
X-ray Diffraction; X-ray Absorption; X-ray photo emission spectroscopy; UV-Vis-IR spectroscopy; Raman Spectroscopy; Tunneling Electron Microscopy; Scanning Electron Microscopy; etc.
EQUIPMENTS in Lab:
X-ray Diffraction; Synthesis lab with 8 furnaces; Gas/Light Sensing; Dielectric and Electrical measurements; Hall measurement, Centrifuge, etc.
SYNTHESIS ROUTES:
Solid state synthesis; Thin film deposition techniques; Sol-gel technique; Hydrothermal technique; Co-precipitation; Electro chemical deposition
Nanoparticles of complex oxide materials are synthesized using different solution based techniques. Sol-gel based materials generally tend to be small but agglomerated. This techniques generally yields extremely high purity single phase materials. Using Hydrothermal technique, generally different morphology of the same material can be produced. However, although doping can be modified the exact amount of doping always remain a undertermined factor. Co-precipitation is a powerful method similar to solgel, which can synthesize pure paze materials but with different morphologies. However, chances of phase segregation is more than solgel process.
All nano particles are anealed in air to explore size dependent properties of the materials.