S. B. Majumder

Bio: S. B. Majumder is an academic researcher from Indian Institute of Technology Kharagpur. The author has contributed to research in topics: Thin film & Dielectric. The author has an hindex of 42, co-authored 248 publications receiving 5664 citations. Previous affiliations of S. B. Majumder include Jadavpur University & University of Puerto Rico at Mayagüez.

Impedance spectroscopy of multiferroic Pb Zr x Ti 1 − x O 3 ∕ Co Fe 2 O 4 layered thin films

Abstract: The electrical properties of ferroelectric $\mathrm{Pb}(\mathrm{Zr},\mathrm{Ti}){\mathrm{O}}_{3}$ (PZT) and ferromagnetic $\mathrm{Co}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ (CFO) thin film multilayers (MLs) fabricated by pulsed laser deposition technique has been studied by impedance and modulus spectroscopy. The effect of various PZT/CFO configurations having three, five, and nine layers has been systematically investigated. The transmission electron microscopy images revealed that the ML structures were at least partially diffused near the interface. Diffraction patterns indicate clear PZT and CFO crystal structures in the interior and at the interface of the ML structure. Room temperature micro-Raman spectra indicate separate PZT and CFO phases in ML structure without any impurity phase. We studied frequency and temperature dependencies of impedance, electric modulus, and ac conductivity of ML thin films in the ranges of $100\phantom{\rule{0.3em}{0ex}}\mathrm{Hz}\char21{}1\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ and $200\char21{}650\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, respectively. We observed two distinct electrical responses in all the investigated ML films at low temperature $(l400\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ and at elevated temperature $(g400\phantom{\rule{0.3em}{0ex}}\mathrm{K})$. We attributed these contributions to the grain effects at low temperature and grain boundary effects at high temperature. We explained this electrical behavior by Maxwell-Wagner-type contributions arising from the interfacial charge at the interface of the ML structure. Master modulus spectra indicate that the magnitude of grain boundary compared to grain becomes more prominent with the increase in the number of layer. The frequency dependent conductivity results well fitted with the double power law, $\ensuremath{\sigma}(\ensuremath{\omega})=\ensuremath{\sigma}(0)+{A}_{1}{\ensuremath{\omega}}^{{n}_{1}}+{A}_{2}{\ensuremath{\omega}}^{{n}_{2}}$, and the results showed evidence of three types of conduction process at elevated temperature: (i) low frequency $(l1\phantom{\rule{0.3em}{0ex}}\mathrm{kHz})$ conductivity is due to long-range ordering (frequency independent), (ii) midfrequency conductivity $(l10\phantom{\rule{0.3em}{0ex}}\mathrm{kHz})$ may be due to the short-range hopping, and (iii) high frequency $(l1\phantom{\rule{0.3em}{0ex}}\mathrm{MHz})$ conduction is due to the localized relaxation hopping mechanism.

Equilibrium, Kinetic, and Thermodynamic Studies of Azo Dye Adsorption from Aqueous Solution by Chemically Modified Lignocellulosic Jute Fiber

Abstract: The lignocellulosic biomass jute fiber (JF) was chemically modified with polyphenolic tannin in aqueous medium by epoxy activation under mild conditions and applied as a potential adsorbent for the removal of Congo Red, a model azo dye, from aqueous solution. The virgin and tannin-modified JF samples were characterized by solid-state nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. Within the studied range of dye concentrations, the adsorption equilibrium was found to follow the Langmuir isotherm model well, with R2 > 0.99. The rate of adsorption of the dye onto treated JF was very high, and equilibrium was attained within 15–30 min of contact. The efficiency of modified JF for the spontaneous and exothermic adsorption of azo dye is attributed to the copious availability of hydroxyl and other polar functional groups on the fiber surface. The present adsorption studies of azo dye from aqueous solution revealed the potential of modified JF t...

Effect of Jute as Fiber Reinforcement Controlling the Hydration Characteristics of Cement Matrix

Abstract: The present investigation deals with the effect of jute as a natural fiber reinforcement on the setting and hydration behavior of cement. The addition of jute fiber in cement matrix increases the setting time and standard water consistency value. The hydration characteristics of fiber reinforced cement were investigated using a variety of analytical techniques including thermal, infrared spectroscopy, X-ray diffraction, and free lime estimation by titration. Through these analyses it was demonstrated that the hydration kinetics of cement is retarded with the increase in jute contents in cement matrix. A model has been proposed to explain the retarded hydration kinetics of jute fiber reinforced cement composites. The prolonged setting of these fiber reinforced cement composites would be beneficial for applications where the premixed cement aggregates are required to be transported from a distant place to the construction site.

Challenges in the development of advanced Li-ion batteries: a review

Abstract: Li-ion battery technology has become very important in recent years as these batteries show great promise as power sources that can lead us to the electric vehicle (EV) revolution. The development of new materials for Li-ion batteries is the focus of research in prominent groups in the field of materials science throughout the world. Li-ion batteries can be considered to be the most impressive success story of modern electrochemistry in the last two decades. They power most of today's portable devices, and seem to overcome the psychological barriers against the use of such high energy density devices on a larger scale for more demanding applications, such as EV. Since this field is advancing rapidly and attracting an increasing number of researchers, it is important to provide current and timely updates of this constantly changing technology. In this review, we describe the key aspects of Li-ion batteries: the basic science behind their operation, the most relevant components, anodes, cathodes, electrolyte solutions, as well as important future directions for R&D of advanced Li-ion batteries for demanding use, such as EV and load-leveling applications.

Multiferroic magnetoelectric composites: Historical perspective, status, and future directions

Abstract: Multiferroic magnetoelectric materials, which simultaneously exhibit ferroelectricity and ferromagnetism, have recently stimulated a sharply increasing number of research activities for their scientific interest and significant technological promise in the novel multifunctional devices. Natural multiferroic single-phase compounds are rare, and their magnetoelectric responses are either relatively weak or occurs at temperatures too low for practical applications. In contrast, multiferroic composites, which incorporate both ferroelectric and ferri-/ferromagnetic phases, typically yield giant magnetoelectric coupling response above room temperature, which makes them ready for technological applications. This review of mostly recent activities begins with a brief summary of the historical perspective of the multiferroic magnetoelectric composites since its appearance in 1972. In such composites the magnetoelectric effect is generated as a product property of a magnetostrictive and a piezoelectric substance. A...

Ferromagnetic materials

Abstract: In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ultracapacitors: Why, How, and Where is the Technology

Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.