Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

We report the synthesis of LaOFeAs based oxypnictide superconductors (La1-xNaxO1-xFxFeAs) using sodium fluoride as a fluorinating agent. NaF doping leads to a systematic decrease in both the a and c lattice parameters. Resistivity measurements show the onset resistivity transition temperature at 30.9 (±0.05) K and corresponding Meissner transition at 28 (±0.05) K in La0.85Na0.15O0.85F0.15FeAs which is highest in LaOFeAs type superconductors synthesized at ambient pressure. Further increase of NaF content in LaOFeAs leads to suppression of Tc. The above superconductors show a negative value of the Seebeck coefficient which indicates that electrons are the dominant charge carriers. © 2009 Elsevier B.V. All rights reserved.

Department of Chemistry

World University root node

Physica C: Superconductivity and its Applications

Compositionally controlled semimetal to superconducting transition in NaF doped LaOFeAs: Enhancement in Tc due to Na-doping

We report the synthesis and characterization of a new electron-doped La-oxypnictide superconductor by partial substitution of lanthanum by thorium. The superconducting transition temperature at about 30.3K was observed in La0.8Th0.2FeAsO, which is the highest in La-based oxypnictide superconductors synthesized at ambient pressure. We find that the decrease in lattice parameters with Th doping in LaOFeAs is more drastic as compared to that obtained by high pressure (6GPa) synthesis of oxygen-deficient LaOFeAs. The resistivity and magnetic susceptibility measurements yield an upper critical field Hc2(0) of 47T. Partial substitution of Th in place of La induces electron doping, as shown by a negative Seebeck coefficient. The temperature-dependent magnetic penetration depth data provides strong evidence for a nodeless low energy gap of 1.4meV. © 2009 IOP Publishing Ltd.

Journal of Physics Condensed Matter

Upper critical field, superconducting energy gaps and the Seebeck coefficient in La0.8Th0.2FeAsO

Here, we report the polymeric (copolymer of benzene and pentacene) nanoparticles (PNPs) induced vertical alignment in ferroelectric liquid crystals (FLCs). The nanoparticles used in this study have been synthesized via chemical route method. The PNPs have been doped in FLC mixture. It has been observed that pentacene molecules (presented in PNPs used) prefer an upright orientation on the indium-tin-oxide-coated surfaces, which in turn provide assistance to align FLC molecules vertically (or homeotropically). It has also been observed that the addition of PNPs into the FLC materials improves the electro-optical response. However, the transition temperatures of the PNPs-doped FLC materials have been lowered. These findings will provide a fascinating tool to align FLC materials devoid of any surface treatment. Moreover, these studies would be helpful in the realization of low threshold and faster liquid crystal display devices. Copyright © EPLA, 2009.

Europhysics Letters

Polymeric-nanoparticles-induced vertical alignment in ferroelectric liquid crystals

We have successfully synthesized Ce based oxypnictide superconductors with fluorine doping (CeO1-xFxFeAs) by a two step solid state reaction method. Detailed XRD and EDX confirm the crystal structure and chemical compositions. We observe that an extremely high Hc2(0) of 94 T can be achieved in the x = 0.1 composition. This increase in Hc2(0) is accompanied by a decrease in transition temperature (38.4 K in x = 0.1 composition) from 42.5 K for the x = 0.2 phase. The in-plane Ginzburg-Landau coherence length is estimated to be ∼27 Å at x = 0.2 suggesting a moderate anisotropy in this class of superconductors. The Seebeck coefficient confirms the majority carrier to be electrons and strong dominance of electron-electron correlations in this multiband superconductor. © 2008 Elsevier B.V. All rights reserved.

Superconductivity in CeO1-xFxFeAs with upper critical field of 94 T

We report significant enhancement in superconducting properties of yttrium substituted Ce1-xYxOFFeAs superconductors. The polycrystalline samples were prepared by two step solid state reaction technique. X-ray diffraction confirmed tetragonal ZrCuSiAs structure with decrease in both a and c lattice parameters on increasing yttrium substitution (with fixed F content). With smaller ion Y in place of Ce, the transition temperature increased by 6 K. Yttrium doping also lead to higher critical fields as well as broader magnetization loops, particularly at elevated temperature. © 2009 American Institute of Physics.

Fulltext

Applied Physics Letters

Enhancement in transition temperature and upper critical field of CeO 0.8F0.2FeAs by yttrium doping

We report the synthesis and characterization of the antimony-doped oxypnictide superconductor, LaO0.8F0.2FeAs 1-xSbx (x = 0.05 and 0.10). The parent compound LaOFeAs with fluorine doping exhibits superconductivity at the maximum transition temperature ∼28.5K (at ambient pressure). Here we partially substitute As by Sb (LaO0.8F0.2FeAs1-xSbx) and observe enhancement of the transition temperature to 30.1K. This is one rare case where Tc increases with doping in the conducting layer (FeAs) and this leads to the highest transition temperature in any La-based oxypnictide. X-ray diffraction and energy-dispersive x-ray analysis measurements confirm the phase purity of the samples and the presence of Sb. The magneto-resistance measurements show that the value of the upper critical field Hc2(0) is about 73T, corresponding to a coherence length (ξGL) of 22. The Seebeck coefficient measurements indicate electron transport with a strong contribution from electron-electron correlation. These results provide interesting insight into the origin of superconductivity in this novel series of compounds. © 2009 IOP Publishing Ltd.

Superconductor Science and Technology

Enhancement of the superconducting transition temperature and upper critical field of LaO0.8F0.2FeAs with antimony doping

The recently discovered superconductors based on oxypnictides have rekindled the search for new non-copper based high-Tc superconductors. After the initial report by Kamihara et al. of superconductivity in (La-O/F-Fe-As)-based compounds, there have been several reports on these new superconductors but the synthesis of pure phases of these oxypnictides has remained a challenge. Here we describe a new methodology of synthesizing these oxypnictide superconductors with the commonly available potassium fluoride (KF) as a source of fluorine instead of the expensive LaF3. This route also allows the substitution of potassium at lanthanum sites which leads to an increase in the upper critical field as would be expected for a multi-band superconductor. We also report the highest-T c (onset) of 28.50 K and highest upper critical field at ambient pressure in the family of La-based oxypnictides. © Europhysics Letters Association.

Potassium fluoride doped LaOFeAs multi-band superconductor: Evidence of extremely high upper critical field

A wide-range memory effect in deformed helix ferroelectric liquid crystals (DHFLCs) has been investigated by electro-optical and textural methods. A comparative study has been performed on strongly and weakly anchored surfaces of DHFLC cells. The saturation voltage has been compared in both types of cells by studying the variation of tilt angle and spontaneous polarization with applied voltage. The long-lasting memory effect has been observed in untreated (weakly anchored) cells. It has been proposed that perfect memory in DHFLC cells without any surface treatment is due to the possibility of the absence of depolarization and ionic charges over the surfaces of the cells. © 2008 The American Physical Society.

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Memory effect in weakly anchored surfaces of deformed helix ferroelectric liquid crystals

Mechanisms inherent in the thermoluminescence (TL) processes are re-investigated with an aim to establish a generalized approach. It has been observed that the extents of recombination and simultaneous retrapping decide the order of kinetics involved. First order kinetics has been found to be a recombination dominant process with negligible or no retrapping. Probabilities of recombination and retrapping are found to be equal in second order kinetics. With the increasing order of kinetics, the extent of recombination decreases alongwith a simultaneous increase in the retrapping. A generalized equation has been developed which is found to be capable of representing the intensities of TL glow curves of different orders of kinetics including that of the first order. It has been found that irrespective of the order of kinetics involved, TL intensity decays exponentially.

Indian Journal of Pure and Applied Physics

Mechanisms inherent in the thermoluminescence processes

Li0.53Na0.03MnO2 compound was prepared by ion exchange from Na0.7MnO2 which was synthesized by the sol-gel method using glycolic acid as a chelating agent. Powder X-ray diffraction and transmission electron microscopy (TEM) confirmed the structure of the as-prepared material resembled that of spinel with a high degree of disorder in the (111) planes. The material delivered a discharge capacity of 200 mA h g-1 after 50 cycles and showed excellent cyclability without undergoing the typical capacity fading exhibited by normal spinel material. It is speculated that the stacking disorder and small particle size of the prepared Li0.53Na0.03MnO2 powder have contributed to prevent the symmetry-breaking transformation which is believed to be responsible for capacity fading.