Shamima Choudhury

• Professor (Full) at University of Dhaka

Nanoscaled magnetic cobalt ferrite (CoFe 2 O 4) of approximately size 17 nm was synthesized via the co-precipitation method and then annealed at 600 • C. The resultant materials were taken for various magnetic characterizations. The X-ray diffraction pattern confirms the formation of the fcc type of cubic crystal structure. The ferrimagnetic phenom...

Manganese (Mn) doped copper (II) oxide (CuO) thin films with 0 to 6 at% Mn doping were prepared onto the glass substrates at a temperature of 523 K using spray pyrolysis technique. The CuO and Mn doped CuO films showed monoclinic structure with the preferential orientation along (1̅11) and (111) planes after being annealed at 723 K in air for 60 mi...

Plasma polymerized 2-vinylpyridine (PP2VP) thin films have been synthesized under glow discharge using a capacitively coupled system. In the scanning electron microscope images, surface morphology of the PP2VP thin films is observed to be very smooth and crack free. Fourier transform infrared spectra of the thin films clearly indicate that structur...

Performance evaluation was conducted for hyperthermia and positive/negative contrast agents incorporating in-vivo angiography studies in Albino Wister rats using folate-chitosan (FC) coated cobalt ferrite (CF) nanoparticles. The structural characterizations were done using X-ray diffraction (XRD), Fourier transforms infrared (FTIR), Raman and Mössb...

Three sets of starting materials Ca(NO3)2·4H2O and (NH4)2HPO4; Ca(OH)2 and H3PO4; Ca(OH)2 and (NH4)2HPO4 were chosen for the preparation of different precursors of hydroxyapatite nanoparticles (n‐HAP) by wet chemical precipitation technique denoted by HAP‐1, HAP‐2, HAP‐3. X‐ray diffraction (XRD) studies show that n‐HAP of all three types exhibited...

Cupric oxide (CuO), an environment friendly p-type transition metal oxide was studied in undoped and doped nanostructured forms by researchers for several potential applications such as solar cells, transistors, gas sensors, etc. In this work, manganese (Mn) doped CuO thin films were prepared onto glass substrates at the substrate temperature of 52...

Undoped, Cerium (Ce) doped, Manganese (Mn) doped and Ce-Mn co-doped Barium Titanate (BaTiO 3) with the general formula Ba 1-x Ce x Mn y Ti 1-y O 3 (where x = 0.00, 0.01, 0.02, 0.03, y = 0.00; x = 0.00, y =0.01, 0.02, 0.03; and x = y = 0.01, 0.02,0.03) were synthesized by solid-state reaction method and sintered at 1200 C for 4 hr with an aim to st...

Nanostructured copper oxide (CuO) thin films have been synthesized onto the glass substrates from aqueous solutions of copper (II) acetate monohydrate precursor salt by a cost effective spray pyrolysis technique at various substrate temperatures between 473 and 673 K. The effects of varying substrate temperature on the structure, surface morphology...

Several strategies have been employed to tune the functional properties of environmentally friendly Barium titanate (BaTiO 3). In this work, bismuth (Bi) doped BaTiO 3 with a general formula Ba 1-x Bi 2x/3 TiO 3 (where x = 0.00, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06) were prepared by the conventional solid-state reaction method. The effect of Bi on...

A series of Co1-xZnxFe2O4 ferrites with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 were synthesized using the standard double sintering ceramic technique. The single-phase cubic spinel structure of the samples was confirmed from the X-ray diffraction patterns and the sharp high intensity peak revealed that the samples are in good crystalline form. The lattic...

Zinc substitution is proposed as an efficient way to improve the performance of the ferrite. In this work, Zinc doped cobalt ferrite with the generic formula CoZnxFe2-xO4, with x = 0.0, 0.1, 0.3 and 0.4 were prepared by conventional ceramic technique, sintered at 1000C for 4 hours in air. The effect of zinc concentration on the initial permeability...

Effect of thickness on structural, optical and morphological properties of 2% copper (Cu) doped zinc selenide (ZnSe) thin films, grown onto chemically and ultrasonically cleaned glass substrate by thermal evaporation method in high vacuum (~10-6 Torr) were studied. Films of 100, 200, 300 and 400 nm thickness were prepared at 200℃ substrate temperat...

Bangladesh has progressed recently from a low- to a medium-developed country. Women, representing 49.4% of a population totaling 158.5 million, have been marching ahead in many sectors for the last few years. The net enrollment rate of girls in primary education is 98.1%, compared to 95.4% for men, and in secondary education the rate is 63.6% women...

•Gender inequality is a global problem except few countries like the Philippines, South Africa etc. •Many female scientists find it challenging to return to active research after starting their families. •During this time, opportunities for women scientists to collaborate in scientific research should be made available. •Bangladesh has been attain...

Ba 1−x Ce x Ti 1−y Mn y O 3 (where x and y varies from 0.00 to 0.03) ceramic samples are synthesized by conventional solid state reaction technique. The samples are sintered at 1473 K for 4 h. The grain size is observed to increase with increasing dopant and co-dopant concentration. The X-ray diffraction confirmed the cubic phase of these BaTiO 3 -...

Women’s contribution in every sphere is a must to build a developed nation, particularly in the science and technology sector. Utilizing women’s talent in science and technology is crucial for sustainable development. Women are hugely underrepresented in the global technology workforce, not only in developing nations like Bangladesh, but also in...

In this investigation, ceramic pellets having the nominal compositions Bi1-xSmxFe1-yTiyO3 (x, y=0.00, 0.03, 0.06) are synthesized by conventional solid-state reaction method and their consequent ultrafine nanoparticles are fabricated using cost-effective ultrasonication method. Accordingly, a comparative investigation between structural and multife...

Cobalt ferrite (CoFe2O4) nanoparticles synthesized by chemical co-precipitation method were studied to see the effect of annealing temperatures on the structural parameters and magnetic properties of the sample. X-ray powder diffraction (XRD), transmission electron microscope (TEM) and SAD pattern demonstrated that single face (fcc) spinel structur...

BANGLADESH started its journey as the so-called ‘bottomless basket’, in some eyes of the west, and now it has come to a point where the rest of the world has become envious for its remarkable success in improving living standards, adequate food production, primary and girl’s enrolment, infant mortality and birth rate control, and micro-finance, etc...

Structural characterization and magnetic properties of Zn-substituted Li ferrites with composition Zn x Li 0.45−x/2 Fe 2.55−x/2 O 4 (where x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) were studied by varying sintering temperature T S (where T S = 1000, 1050, 1100, 1150, 1200, and 1250 • C) of the six samples. The single-phase cubic spinel structure was fo...

Zinc ferrite samples were prepared by two different routes which are chemical co-precipitation and standard solid state double sintering method. Structural properties of ZnFe2O4 were determined, and initial particle size was found as 5 nm in the samples prepared by chemical co-precipitation technique. The XRD patterns showed the single phase of ZnF...

p>Synthesis and characterization of BiFeO3 samples, co-doped with rare earth Nd and Co in place of Bi and Fe respectively were investigated at room temperature (RT). The formula of the four samples are Co-doped BiFe_1–xCo_xO₃ (x = 0.05-0.10) and Nd and Co co-substituted Bi_0.95Nd_0.05Fe<sub>0.95</s...

p>To observe the impact of the annealing time on the alloy structure and ultra-soft magnetic properties of Fe_75.5Si_13.5Cu₁Nb₁B₉, the alloy was annealed in a controlled way in the temperature range 475 - 600^°C for different annealing time from 5 to 30 min. Amorphosity of the ribbon an...

p>Effects of indium doping (concentration 0.2, 0.3 and 0.4%) on the optical properties of GaAs thin films were studied. Thin films of 600 nm were grown onto chemically and ultrasonically cleaned glass substrate by thermal evaporation method in high vacuum (~10-4 Pa) at 50°C fixed substrate temperature. The samples were annealed for 15 minutes at a...

Nanostructured ZnFe2O4 ferrites are prepared using chemical co-precipitation method and their corresponding bulk counterpart are prepared using standard double sintering method. Structural properties are determined from X-ray diffraction line broadening for both nanostructured and bulk (>1000nm) ZnFe2O4. The XRD patterns show single phase of ZnFe2O...

Indium doped Tin oxide (SnO2: In) thin films of various thicknesses (200-600 nm) with fixed 2% indium (In) concentration were prepared by thermal evaporation method onto glass substrates under high vacuum (10-6 Torr). As deposited films were vacuum annealed at 200o C for 60 minutes. The structure, optical, electrical and morphology properties of Sn...

The effect of annealing condition on nanocrystalline amorphous FINEMET type of alloy with nominal composition Fe74Cu1.5Nb2.5Si12B10 prepared by rapid solidification method has been studied to observe the structural properties and crystallization behavior of the material. Nanocrystalline alloy with ferromagnetic bcc nanocrystals with size 15-29 nm e...

p>Pure and magnesium (Mg) doped zinc oxide (ZnO) thin films were prepared onto clean glass substrate by spray pyrolysis (SP) technique at the substrate temperature of 300^°C. Various optical parameters such as absorption co-efficient, band gap energy, refractive index, extinction coefficient of the thin films were studied using UV-VIS-NIR...

Indium doped Tin Oxide

A detailed study of magnetic softness has been performed on FINEMENT type of ribbons by investigating the BH loop with maximum applied field of 960 A/m. The ribbon with the composition of Fe74Cu0.8Nb2.7Si15.5B7 was synthesized by rapid solidification technique and the compositions volume fraction was controlled by changing the annealing condition....

Pure and magnesium (Mg) doped zinc oxide (ZnO) thin films were prepared onto clean glass substrate by spray pyrolysis (SP) technique at the substrate temperature of 300°C. Various optical parameters such as absorption co-efficient, band gap energy, refractive index, extinction co-efficient of the thin films were studied using UV-VIS-NIR spectrophot...

Nanostructured ZnFe2O4 ferrites are prepared using chemical co-precipitation method and their corresponding bulk counterpart are prepared using standard double sintering method. Structural properties are determined from x-ray diffraction line broadening for both nanostructured and bulk (>1000nm) ZnFe2O4. The XRD patterns show single phase of ZnFe2O...

Structural properties of Zn-Li ferrites with the composition ZnxLi0.45-x/2Fe2.55-x/2O4 (where, x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) synthesized by conventional ceramic method have been investigated as a function of Zn content and sintering temperature TS (where TS=1000, 1050, 1100, 1150, 1200 and 1250oC). The X-ray diffraction (XRD) analysis confir...

Polycrystalline NiFe2O4 samples were prepared from analytical grade powder of NiO and Fe2O3 by conventional double sintering technique. The samples were sintered at 1000 - 1400°C. The scanning electron micrographs (magnification ´ 10000) of the samples revealed that the grain size increases and the porosity decreases with the increase in sintering...

The nominal compositions of Bi 1-y Nd y Fe 1–x Co x O 3 (i. y=0, x=0.05 ; ii. y=0, x=0.10 ; iii. y=0.05, x=0.05 ; iv. y = 0.10, x = 0.10) ceramics were synthesized by conventional solid state reaction technique and their dielectric and magnetic properties were investigated at room temperature. The X-ray diffraction patterns clearly indicate that th...

Electrical, optical and structural properties of p-type single crystal silicon were investigated in this work. Electrical conductivity of p-type silicon was measured in the temperature ranges 190-300 K. The acceptor ionization energy ((E A) was between 0.047-0.051 eV. Photoconductivity of the material was investigated by varying sample current, lig...

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abstract Biomedical applications of ZnFe2O4 nanoparticle are preferable among all kinds of ferrites due to the compatibility of Zn2 þ ions for human bodies. We have followed the soft chemical route to synthesize chitosan and PEG coated ZnFe2O4 nanoparticles and also the chitosan-coated-nanoparticles encapsulated with liposome. X-ray diffraction stu...

The effects of Li 2 O additives on the structural, magnetic and electrical properties of Ni 0.5 Mg 0.5 Fe 2 O 4 , prepared by conventional double sintering ceramic technique were investigated. The X-ray diffraction (XRD) pattern of the prepared samples showed single phase cubic spinel structure. Variation of lattice parameter has been observed with...

Optical and structural characterization of Zinc Selenide (ZnSe) thin films (thickness ranging between 200 - 500 nm) prepared by vacuum (~10-6 Torr) evaporation method were investigated. The thin films were deposited with varying substrate temperature in the range 373 - 573K. Optical measurements were carried out with UV-VIS-NIR spectrophotometer wi...

Electrical, optical and structural properties of p-type single crystal Silicon were investigated. Electrical conductivity was measured in the temperature ranges 196K-299K. The acceptor ionization energy (ΔE‪ A) obtained from the graphs was 0.051 eV. Photoconductivity of the same samples was also investigated under different conditions (varying samp...

Nanocrystalline amorphous FINEMET alloy with a nominal composition Fe74Cu1.5Nb2.5Si12B10 prepared by a rapid solidification method was annealed in a controlled way in the temperature range 475–650 °C for 15 minutes in order to study the structural parameters such as grain size, Si content and lattice parameter of the nanocrystalline Fe(Si) nanograi...

Substrate temperature dependent optical and structural properties of Cadmium Telluride (CdTe) thin films were studied. Films were grown onto glass substrate by thermal evaporation method in high vacuum (10^-6 Torr) with varying thickness (200 ~ 500 nm). All the films were characterized optically by UV-VIS-NIR spectrophotometer in photon wavelength...

The electrical transport properties of ZnxLi0. 45-x/2Fe2. 55-x/2O4 (where, x= 0.0, 0.3, 0.5) synthesized by conventional ceramic method have been investigated as a function of Zn content. The X-ray analysis confirms the formation of single phase cubic spinel structure. The ac resistivity and dielectric constant show opposite trend with increase...

Women succeed in science as a result of their own merit, initiative and drive. Family support, institutional support and most importantly government support are very important for women to succeed in their professional career. At present success remains an exception, not the rule as the women have to face challenges at all levels of ladder in their...

A series of Cu1-x Znx Fe2O4 ferrite (with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) compositions were synthesized using the standard solid-state reaction technique. X-ray diffraction was used to study the structure of the above investigated samples. The theoretical and experimental lattice parameters (a th and a exp) were calculated for each compositi...

Effect of thickness on the optical and electrical properties of gallium arsenide (GaAs) thin films were studied. The films of different thicknesses were prepared by vacuum evaporation method (~10^-4 Pa) on glass substrates at a substrate temperature of 323 K. The film thickness was measured in situ by a frequency shift of quartz crystal. The thickn...

Bangladesh has had a glorious physics tradition since the beginning of the last century, when the physicist S.N. Bose published a groundbreaking paper with Albert Einstein on Bose-Einstein statistics. However, women in Bangladesh traditionally have not been able to make their way in the realm of science in general and physics in particular. Since B...

The effect of compositional variation on the structure and magnetic properties of Ni-Mg ferrites with compositions Ni1.xMg xFe2O4 for [x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0], prepared by a conventional double sintering ceramic technique, sintered at 1350 °C for 4.5 hours were investigated. The structural characterization of the samples has been perf...

Effect of thickness on the optical and electrical properties of gallium arsenide (GaAs) thin films were studied. The films of different thicknesses were prepared by vacuum evaporation method (~10-4 Pa) on glass substrates at a substrate temperature of 323 K. The film thickness was measured in situ by a frequency shift of quartz crystal. The thickne...

Effect of Zn content on the dielectric and transport properties of CoZn x Fe 2-x O 4 (x = 0.0, 0.1, 0.2, 0.3 and 0.4), prepared by standard double sintering ceramic technique, sintered at 1000 o C for 4 hours were investigated. The X-ray diffraction (XRD) pattern of the prepared samples showed single phase inverse-spinel structure without any detec...

Nano size NiO and Fe2O3 have been prepared by chemical co-precipitation technique. In the as dried condition for the formation of NiO nanoparticles, the compound has been identified as Ni(OH)2. Then upon systematic variation of calcination temperatures (200-10000C), NiO nanoparticles from 6 nm to about 40 nm have been calculated from XRD data by us...

Nanotechnology and Economic Challenges in Bangladesh Shamima K Choudhury Department of Physics, University of Dhaka, Dhaka-1000, Bangladesh Email: skc.phy@gmail.com; shamima@univdhaka.edu Bangladesh is a low human developed country with HDI of 0.50 with a rank of 146 out of 187 countries. Compared to other developing countries, it has a highly den...

Polycrystalline NiFe 2 O 4 was prepared from Analytical Grade powder of NiO and Fe 2 O 3 by conventional double sintering technique. The apparent density of the prepared sample increases with the increase in sintering temperature and consequently the porosity decreases which has a great influence on electrical and dielectric properties of soft ferr...

Electrical properties such as electrical resistivity, Hall coefficient, Hall mobility, carrier concentration of p-type GaAs samples were studied at room temperature (300 K). Resistivity was found to be of the order of 5.6 × 10 -3 Ω-cm. The Hall coefficient (R H) was calculated to be 7.69 × 10 -1 cm 3 /C and Hall mobility (µ H) was found to be 131cm...

Polycrystalline NiFe2O4 was prepared by solid-state reaction from nanosize powders of NiO and Fe2O3 which were synthesized by wet chemical method. Enhancement of apparent density of the sample has been observed with the increase in sintering temperature and has great influence on the transport properties of NiFe2O4. Decrease in resistivity with inc...

The structural and electrical properties of pure and manganese doped barium titanate (BaTiO3) with a general formula BaMnxTi1-xO3 (where x= 0.00, 0.01, 0.02, 0.03, and 0.04) were investigated. For the observation of the surface morphology and estimation of grain sizes scanning electron microscopy (SEM) was employed. The grain size of BaTiO3 inc...

The magnetic and structural properties of FINEMET alloy with a composition of Fe75.5Cu1Nb1Si13.5B9 were investigated after primary and secondary crystallization of amorphous ribbon sample. The crystallization behavior and the nanocrystal formation of the samples were performed by differential thermal analysis (DTA) which in turn was supported by X-...

Structural and magnetic measurements have been performed on the FINEMET type of ribbons with nominal composition of Fe74Cu0.5Nb3Si13.5B9 synthesized by rapid solidification technique. The crystallization behavior and the nanocrystal formation have been studied by differential thermal analysis (DTA) and X-ray diffraction (XRD). The crystallization o...

Nanocrystalline amorphous ribbons of composition Fe70.5 Cr3 Cu1 Nb3 Si13.5 B9 prepared by rapid solid- ification technique have been studied in the present work. Amorphicity of the ribbons has been confirmed by X-ray diffraction. Crystallization temperatures were identified by X-ray diffraction and crystallization products were analyzed by XRD. Whe...

A solid state reaction method was used to synthesize barium titanate (BT) and barium cerium titanate (BCT) ceramics at sintering temperature of 1473 K for 4 h. The effect of cerium (Ce) on the structure, microstructure and dielectric properties of BCT was investigated. The scanning electron microscopy (SEM) investigations revealed that the grain si...

Barium titanate (BaTiO 3) and cerium (Ce) doped BaTiO 3 samples were prepared by the standard solid state reaction method and were sintered at 1473 K for four hours. The structural and dielectric properties of the samples were studied. The x-ray diffraction results showed mostly the BaTiO 3 phase where the lattice parameter decreased with the addit...

Thin films of Tin Oxide (SnO 2), having thickness of 200 nm, were formed on to glass substrates by thermal evaporation of high-purity SnO 2 powder in vacuum at various substrate temperatures (T S), ranging between 25 and 200C. SnO 2 films with varying thickness were also prepared for a fixed T S = 100C. Further, doping of SnO 2 films with Indium...

Zn doped Cu ferrite of the composition Cu 1-x Zn x Fe 2 O 4 ferrites for x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 prepared by standard double sintering ceramic technique. SEM micrograph of all the samples revealed that the grain sizes decrease gradually with the increase of Zn content and has great influence on the magnetic and transport properties. Per...