Sandwip Dey

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Towards self-powered photo-electrochromic systems via cost effective integration of Metal-ZnS/ZnO Schottky junctions

Selectively deposited Ru top electrode on Pb(Zr[sub 0.3]Ti[sub 0.7])O[sub 3] and Ru step coverage on TiN by digital chemical vapor deposition

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2004

A digital chemical vapor deposition (DCVD) process was used to selectively deposit ruthenium on h... more

Highly textured Pb(Zr0.3Ti0.7)O3 thin films on GaN/sapphire by metalorganic chemical vapor deposition

Journal of Materials Research, 2006

Highly (111) textured Pb(Zr0.3Ti0.7)O3 (PZT 30/70) films were deposited on (0001) GaN/sapphire su... more Highly (111) textured Pb(Zr0.3Ti0.7)O3 (PZT 30/70) films were deposited on (0001) GaN/sapphire substrates using liquid-source metalorganic chemical vapor deposition (MOCVD) technique at 520 °C and 80 nm/min. The crystallinity of as-deposited PZT films and the structure of PZT/GaN interface were evaluated by x-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM), respectively. Mitigated by geometric epitaxy and strain energy minimization, the orientation relationships of PZT on epi-GaN, determined using x-ray pole figure and selected area diffraction pattern, were as follows: out-of-plane alignment of [111] PZT//[0001] GaN, and orthogonal in-plane alignments of [112] PZT//[1100] GaN (zone axes) and [110] PZT//[1120] GaN. The nanochemistry of the PZT (150nm)/GaN interface, studied using analytical TEM, indicated a chemically sharp interface with interdiffusion limited to a region below 5 nm. The properties of as-deposited PZT on GaN by MOCVD are briefly c...

Ferroelectric thin-film memory for electrically programmable IC neural networks

Ferroelectrics, 1991

The application of ferroelectric thin-film capacitors as connection element synapses in artific... more

Integrated Ferroelectrics: Guest editorial

Integrated Ferroelectrics, Nov 1, 2006

Silica diatom nanopore membranes combined with silicon MEMS

Vapor-Transport Synthesis and Annealing Study of ZnxMg1–xO Nanowire Arrays for Selective, Solar-Blind UV-C Detection

ACS Omega, 2018

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Transmission electron microscopy observations of sol-gel derived ferroelectric PbZrO 3 -PbTiO 3 thin films with excess PbO

Integrated Ferroelectrics, 1994

This paper presents general transmission electron microscopy observations of polymeric sol-gel de... more This paper presents general transmission electron microscopy observations of polymeric sol-gel derived PZT(52/48) thin films that were heat treated in a conventional furnace for 1 hour at 700[ddot]C. Results from high resolution TEM, EDS and EELS are also included. The thin films revealed a complex microstructure with dispersed nanocrystalline PbO second phase, embedded porosity, local chemical inhomogeneities, and residual organics.

Rapid Synthesis of Electrode Materials (Li4Ti5O12 and LiFePO4) for Lithium ion Batteries through Microwave Enhanced Processing Techniques

by K. A. Cherian and Sandwip Dey

… in Alternative and …, 2010

Page 1. Batteries and Energy Storage Materials Materials Challenges in Alternative and Renewable ... more

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Synthesis, Characterization, andIn VitroDrug Delivery Capabilities of (Zn, Al)-Based Layered Double Hydroxide Nanoparticles

Journal of Nanotechnology, 2015

There is an urgent need for the development of alternative strategies for effective drug delivery... more There is an urgent need for the development of alternative strategies for effective drug delivery to improve the outcome of patients suffering from deadly diseases such as cancer. Nanoparticles, in particular layered double hydroxide (LDH) nanoparticles, have great potential as nanocarriers of chemotherapeutic molecules. In this study, we synthesized (Zn, Al)-LDH nanoparticles and report their enhanced pH-dependent stability in comparison to the commonly used (Mg, Al)-LDH nanoparticles. Fluorescein isothiocyanate (FITC) and valproate (VP) were intercalated into (Zn, Al)-LDH nanoparticles to study cellular uptake, biocompatibility, and drug delivery capabilities using cultured pancreatic adenocarcinoma BxPC3 cells. Fluorescence measurements indicated that FITC-intercalated LDH nanoparticles showed a greater degree of energy-dependent uptake rather than passive uptake by BxPC3 cells, especially at high concentrations of nanoparticles. Tetrazolium-based colorimetric assays indicated th...

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Chemical bath deposition of nanocrystalline (111) textured Ag2Se thin films

Materials Letters, 2000

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Inorganic nanoparticles for cancer imaging and therapy

Journal of Controlled Release, 2011

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Analyses of Substrate-Dependent Broadband Microwave (1–40 GHz) Dielectric Properties of Pulsed Laser Deposited Ba0.5Sr0.5TiO3 Films

Crystals

Ba0.5Sr0.5TiO3 (BST-0.5) thin films (600 nm) were deposited on single crystal MgO, SrTiO3 (STO), ... more Ba0.5Sr0.5TiO3 (BST-0.5) thin films (600 nm) were deposited on single crystal MgO, SrTiO3 (STO), and LaAlO3 (LAO) substrates by pulsed laser deposition at an oxygen partial pressure of 80 mTorr and temperature of 720 °C. X-ray diffraction and in situ reflection high-energy electron diffraction routinely ascertained the epitaxial quality of the (100)-oriented nanocrystalline films. The broadband microwave (1–40 GHz) dielectric properties were measured using coplanar waveguide transmission line test structures. The out-of-plane relative permittivity (ε⏊/) exhibited strong substrate-dependent dielectric (relaxation) dispersions with their attendant peaks in loss tangent (tanδ), with the former dropping sharply from tens of thousands to ~1000 by 10 GHz. Although homogeneous in-plane strain (ϵǁ), enhances ε⏊/ with εMgOBST−0.5⏊/>εSTOBST−0.5⏊/>εLAOBST−0.5⏊/ at lower frequencies, two crossover points at 8.6 GHz and 18 GHz eventually change the trend to: εSTOBST−0.5⏊/>εLAOBST−0.5⏊/...

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Rapid Synthesis of Electrode Materials (Li4 Ti5 O12 and LiFePO4 ) for Lithium ion Batteries through Microwave Enhanced Processing Techniques

Ceramic Transactions Series

Page 1. Batteries and Energy Storage Materials Materials Challenges in Alternative and Renewable ... more

2006 SYMPOSIUM ORGANIZERS ISIF Organization General Co-Chairs

Magnetic properties of press-forged barium ferrite

American Ceramic Society Bulletin, 1985

Preparation de poudres de ferrite de baryum submicroniques par calcination d'un melange de Ba... more Preparation de poudres de ferrite de baryum submicroniques par calcination d'un melange de BaCO 3 et de Fe 2 O 3 en presence de CaF 2 . On examine les proprietes magnetiques des materiaux obtenus par pressage de la poudre a 1050°-1125°C. On etudie les correlations entre ces proprietes, les caracteristiques initiales de la poudre et les parametres de fabrication

Structure of polymeric PbTiO/sub 3/ gels

The structural features of PbTiO/sub 3/ gels were found to be highly dependent on hydrolysis cond... more The structural features of PbTiO/sub 3/ gels were found to be highly dependent on hydrolysis conditions. Gels formed from acid-catalyzed solutions were clear and rubbery, whereas base-catalyzed gels were translucent or cloudy with phase separation. Direct TEM observations determined that acid-catalyzed gels were fibrous in character and physically homogeneous, whereas base-catalyzed gels had a coarse texture. Analyses by EDX and SAD indicated that acidic gels were chemically homogeneous and microcrystalline, whereas basic gels were heterogeneous and amorphous.

SOL-GEL PROCESSING OF PbTiO//3, PbZrO//3, PZT, AND PLZT THIN FILMS

Thin films were fabricated in the PLZT system by spin-casting solutions of complex alkoxides prep... more

Synthesis and Characterization of Silver (Core)/Layered Double Hydroxides (Shell) Nanoparticles

Layered double hydroxide (LDH) is well-known for its versatile capability of electrostatic bindin... more Layered double hydroxide (LDH) is well-known for its versatile capability of electrostatic binding or intercalation of anions. Nanoparticles (NPs) based on Ag core and LDH shell, with surface plasmon resonance (SPR) of Ag for hyperthermia and drug intercalation capability in LDH shell, hold promise in Nanomedicine. Herein, for the first time, noble metal, Ag, (core)/(Mg2+, Al3+)-LDH (shell) NPs were synthesized. Morphology, composition and SPR of obtained core/shell NPs were fully characterized. Core/shell NPs of 45 nm Ag NP core with various LDH shell thickness from 10 to 15 nm were obtained. For the 45 nm Ag NP core, the wavelength for transverse SPR absorption was 395 nm, which red-shifted up to 430 nm at a LDH shell thickness of 15 nm. Parallelly, the synthesis and characterization of the Ag nanorod are also reported. Exhibition of longitudinal SPR absorption in the targeted near infrared range make it a more appropriate core.

Microstructural and Dielectric Properties of High Permittivity (Pb, Ba) ZrO3 Thin Films by Sol-Gel Processing

High permittivity (Pb0.7, Ba0.3)ZrO3 (PBZ) films (60–110 nm) were fabricated by sol-gel processin... more High permittivity (Pb0.7, Ba0.3)ZrO3 (PBZ) films (60–110 nm) were fabricated by sol-gel processing on (111) Pt-passivated Si substrates, followed by rapid thermal annealing (RTA) at 550–700°C for 5 minutes in oxygen. The randomly oriented grains were of the crystalline perovskite phase, with minor amounts of amorphous or nanocrystalline phase in the intergranular regions. The microstructure of the PBZ films was markedly influenced by substrate annealing and RTA temperature. At 10 kHz, the low-field dielectric permittivity and loss tangent of a 66 nm PBZ film were measured to be 932 and 0.03, respectively, giving a C/A of 12.5 µF/cm2.