scholarly journals Influence of Bath Composition on the Electrodeposited \(\text{Co-Ni-P}\) Nanowires

2014 ◽  
Vol 24 (3S1) ◽  
pp. 90-94
Author(s):  
Luu Van Thiem ◽  
Le Tuan Tu ◽  
Pham Duc Thang
Keyword(s):  
Crystal Structure ◽  
Magnetic Measurements ◽  
Nanowire Arrays ◽  
Morphological Properties ◽  
Solution Ph ◽  
X Ray ◽  
Ph Values ◽  
Transmission Electron ◽  
Magnetization Hysteresis Loop ◽  
Hcp Structure

CoNiP nanowire arrays were fabricated by electrodeposition method into polycarbonate (PC) templates at different pH values. It is obvious that the crystal structure of the CoNiP nanowires depends on the pH values of electrolyte. The XRD results show that crystal structure of the CoNiP nanowires is hcp structure and the intensity of the hcp (002) increased enhances as solution pH =5. Magnetic measurements indicate a dependence of the squareness and the coercivity of the magnetization hysteresis loop on pH values with a maximum coercivity of 1425 Oe. The morphological properties of CoNiP nanowires were studied by transmission electron microscopy (TEM). The chemical composition was determined by examination of the energy dispersive X-ray (EDS) spectra and the magnetic properties were measured by vibrating sample magnetometry (VSM).

Crystalline phase transformation of colloidal cadmium sulfide nanocrystals

2017 ◽  
Vol 31 (06) ◽  
pp. 1750037
Author(s):  
M. Ghali ◽  
A. M. Eissa ◽  
M. M. Mosaad
Keyword(s):  
Phase Transformation ◽  
Optical Absorption ◽  
Crystalline Phase ◽  
Growth Conditions ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Ph Values ◽  
Transmission Electron

In this paper, we give a microscopic view concerning influence of the growth conditions on the physical properties of nanocrystals (NCs) thin films made of CdS, prepared using chemical bath deposition CBD technique. We show a crystalline phase transformation of CdS NCs from hexagonal wurtzite (W) structure to cubic zincblende (ZB) when the growth conditions change, particularly the solution pH values. This effect was confirmed using X-ray diffraction (XRD), transmission electron microscopy (TEM), optical absorption and photoluminescence (PL) measurements. The optical absorption spectra allow calculation of the bandgap value, [Formula: see text], where significant increase [Formula: see text]200 meV in the CdS bandgap when transforming from Hexagonal to Cubic phase was found.

scholarly journals Dissimilatory Iron-Reducing Microorganisms Are Present and Active in the Sediments of the Doce River and Tributaries Impacted by Iron Mine Tailings from the Collapsed Fundão Dam (Mariana, MG, Brazil)

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 244
Author(s):  
Carolina N. Keim ◽  
Jilder D. P. Serna ◽  
Daniel Acosta-Avalos ◽  
Reiner Neumann ◽  
Alex S. Silva ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
Magnetic Measurements ◽  
Culture Media ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferric Oxyhydroxide ◽  
Transmission Electron ◽  
Iron Mine ◽  
Organic Matter Oxidation ◽  
Doce River

On 5 November 2015, a large tailing deposit failed in Brazil, releasing an estimated 32.6 to 62 million m3 of iron mining tailings into the environment. Tailings from the Fundão Dam flowed down through the Gualaxo do Norte and Carmo riverbeds and floodplains and reached the Doce River. Since then, bottom sediments have become enriched in Fe(III) oxyhydroxides. Dissimilatory iron-reducing microorganisms (DIRMs) are anaerobes able to couple organic matter oxidation to Fe(III) reduction, producing CO2 and Fe(II), which can precipitate as magnetite (FeO·Fe2O3) and other Fe(II) minerals. In this work, we investigated the presence of DIRMs in affected and non-affected bottom sediments of the Gualaxo do Norte and Doce Rivers. The increase in Fe(II) concentrations in culture media over time indicated the presence of Fe(III)-reducing microorganisms in all sediments tested, which could reduce Fe(III) from both tailings and amorphous ferric oxyhydroxide. Half of our enrichment cultures converted amorphous Fe(III) oxyhydroxide into magnetite, which was characterized by X-ray diffraction, transmission electron microscopy, and magnetic measurements. The conversion of solid Fe(III) phases to soluble Fe(II) and/or magnetite is characteristic of DIRM cultures. The presence of DIRMs in the sediments of the Doce River and tributaries points to the possibility of reductive dissolution of goethite (α-FeOOH) and/or hematite (α-Fe2O3) from sediments, along with the consumption of organics, release of trace elements, and impairment of water quality.

scholarly journals Structural Evolution in Wet Mechanically Alloyed Co-Fe-(Ta,W)-B Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 800
Author(s):  
Vladimír Girman ◽  
Maksym Lisnichuk ◽  
Daria Yudina ◽  
Miloš Matvija ◽  
Pavol Sovák ◽  
...  
Keyword(s):  
Structural Changes ◽  
Magnetic Measurements ◽  
Structural Evolution ◽  
High Energy ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Absorption

In the present study, the effect of wet mechanical alloying (MA) on the glass-forming ability (GFA) of Co43Fe20X5.5B31.5 (X = Ta, W) alloys was studied. The structural evolution during MA was investigated using high-energy X-ray diffraction, X-ray absorption spectroscopy, high-resolution transmission electron microscopy and magnetic measurements. Pair distribution function and extended X-ray absorption fine structure spectroscopy were used to characterize local atomic structure at various stages of MA. Besides structural changes, the magnetic properties of both compositions were investigated employing a vibrating sample magnetometer and thermomagnetic measurements. It was shown that using hexane as a process control agent during wet MA resulted in the formation of fully amorphous Co-Fe-Ta-B powder material at a shorter milling time (100 h) as compared to dry MA. It has also been shown that substituting Ta with W effectively suppresses GFA. After 100 h of MA of Co-Fe-W-B mixture, a nanocomposite material consisting of amorphous and nanocrystalline bcc-W phase was synthesized.

Influence of Alloying Additions on Enhancement of Soft Magnetic Properties Effect and Crystallization in FeXSiB (X=Cu, V, Co, Zr, Nb) Amorphous Alloys

2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Crystallization Process ◽  
Annealing Temperature ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray ◽  
Second Stage ◽  
Transmission Electron

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.

Fabrication, characterization and magnetic properties of Na-doped ZnO nanorods

2016 ◽  
Vol 09 (03) ◽  
pp. 1650039 ◽  
Author(s):  
Jingyuan Piao ◽  
Li-Ting Tseng ◽  
Kiyonori Suzuki ◽  
Jiabao Yi
Keyword(s):  
Magnetic Measurements ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Shallow Donors ◽  
Na Doping ◽  
Transmission Electron ◽  
Doped Zno ◽  
Electron Paramagnetic

Na-doped ZnO nanorods have been fabricated through a hydrothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicate that the d spacing of ZnO increases with increasing doping concentration, suggesting the effective incorporation of dopant Na in the samples. Electron paramagnetic resonance (EPR) measurements indicate that there are shallow donors in pure ZnO samples and the shallow donors are strongly prohibited by Na doping. In addition, the resonance at g = 2.005 suggests the formation of Zn vacancies. Magnetic measurements indicate that pure ZnO is paramagnetic and Na doping leads to ferromagnetism at room temperature. Moreover, 0.5% Na-doped ZnO nanorods exhibits the largest saturation magnetization.

Cyano-Bridged Bimetallic Complexes of Copper(II) with Nitroprusside. Crystal Structure of [Cu(H2NCH2CH(NH2)CH3)2Fe(CN)5NO] . H2O

2000 ◽  
Vol 53 (3) ◽  
pp. 225 ◽  
Author(s):  
Zdenek Smékal ◽  
Zdenek Trávnícek ◽  
Jaromír Marek ◽  
Milan Nádvornik
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Magnetic Measurements ◽  
X Ray ◽  
Cyanide Group ◽  
Cyanide Ligand ◽  
Binuclear Structure ◽  
Tetragonal Pyramidal ◽  
Cyanide Ligands ◽  
Diamine Ligands

Five new complexes of compositions [Cu(1,2-pn)2Fe(CN)5NO]·H2O (1,2-pn = propane-1,2-diamine) and [Cu(L)Fe(CN)5NO]·xH2O (L = tmen (N,N,N′,N′-tetramethylethane-1,2-diamine), x = 0.5; L = trimeen (N,N,N′-trimethylethane-1,2-diamine), x = 1; L = dien (N-(2-aminoethyl)ethane-1,2-diamine), x = 0; L = medpt (N-(3-aminopropyl)-N-methylpropane-1,3-diamine), x = 2) have been isolated from the reaction mixture of Cu(ClO4)2·6H2O (or CuCl2·2H2O), the amine and Na2 [Fe(CN)5NO]·2H2O in water. The complexes have been characterized by infrared and ultraviolet–visible spectroscopies, and magnetic measurements. Single-crystal X-ray structural analysis revealed that the [Cu(1,2-pn)2Fe(CN)5NO]·H2O complex assumes a cyanide-bridged binuclear structure in which iron(II) is six-coordinated by five cyanide ligands and one nitrosyl group (the nitrosyl group lies cis to the bridging cyanide group), while copper(II) is five-coordinated by two propane-1,2-diamine ligands and a bridging cyanide ligand in a distorted tetragonal pyramidal arrangement.

Eco-Friendly Preparation of Nanofibrillated Cellulose from Water Hyacinth Using NaOH/Urea Pretreatment

2020 ◽  
Vol 990 ◽  
pp. 225-230
Author(s):  
Kraiwit Pakutsah ◽  
Duangdao Aht-Ong
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Water Hyacinth ◽  
Aqueous Suspension ◽  
Nanofibrillated Cellulose ◽  
Cellulose Ii ◽  
Cellulose I ◽  
X Ray ◽  
Transmission Electron ◽  
Water Hyacinth Fiber

In this work, we described an effective approach to prepare nanofibrillated cellulose (NFC) with cellulose II structure under mild condition. Firstly, the water hyacinth (WH) was subjected to a series of a two-step chemical treatment, NaOH/urea pretreatment, and mechanical defibrillation at different defibrillation times. After that, raw water hyacinth fiber (RWF), bleached water hyacinth fiber (BWF), NaOH/urea pretreated water hyacinth fiber (PWF), and the resulting NFC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) as well as rheological measurements. It was found that RWF and BWF exhibited cellulose I crystal structure, whereas PWF and the obtained NFC possessed cellulose II crystal structure. FTIR analysis confirmed the evidence that no other chemical reactions preferentially occurred during both NaOH/urea pretreatment and mechanical defibrillation. As evidenced by rheological properties analysis, the NFC aqueous suspension with a gel-like structure demonstrated a shear-thinning behavior. The obtained NFC could potentially be utilized as a reinforcement for polymeric composites.

Magnetic and Structural Properties of Ferrimagnetic Bioceramics

2005 ◽  
Vol 473-474 ◽  
pp. 117-122 ◽  
Author(s):  
A.C. Kis ◽  
Th. Leventouri ◽  
J.R. Thompson
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Calcium Phosphate ◽  
Powder Diffraction ◽  
Magnetic Measurements ◽  
Treatment Temperature ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Phase Development

Structure and magnetic properties of ferrimagnetic bioceramics in the system {0.45(CaO, P2O5) ySiO2 xFe2O3 0.03Na2O}, x=0.05, 0.10, 0.15, 0.20, were studied by x-ray powder diffraction and magnetic measurements. Magnetite and calcium phosphate, crystallizing in the hexagonal and monoclinic crystal systems, are the major phases in the compounds. Phase development, crystal structure, and magnetic properties of the composites are determined by the specific starting composition of oxides and the heat-treatment temperature.

Synthesen, Kristallstrukturen und magnetische Eigenschaften von [Li(12-Krone-4)2][Li(12-Krone-4)(OH2)]2[Nb6Cl18], [Li(15-Krone-5)2(OH2)]3[Nb6Cl18] und [(18-Krone-6)2(O2H5)]3[Nb6Cl18] / Syntheses, Crystal Structures and Magnetic Behaviour of [Li(12-Krone-4)2][Li(12-Krone-4)(OH2)]2[Nb6Cl18], [Li(15-Krone-5)2(OH2)]3[Nb6Cl18] and [(18-Krone-6)2(O2H5)]3[Nb6Cl18]

2001 ◽  
Vol 56 (10) ◽  
pp. 1025-1034 ◽  
Author(s):  
Markus Ströbele ◽  
H.-Jtirgen Meyer
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Crown Ethers ◽  
Magnetic Measurements ◽  
Structure Refinement ◽  
Magnetic Behaviour ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Paramagnetic Behaviour

The title compounds were prepared through reactions of Li2Nb6Cl16 with the corresponding crown ethers in acetone. All three compounds were obtained as dark brown crystals. Their structures were solved with the means of single-crystal X-ray diffraction.[Li(12-crown-4)2][Li(12-crown-4)(OH2)]2[Nb6Cl18]: space group P21/n, Z =2, a = 1320.4(1), b = 1879.1(1), c = 1321.7(1) pm, ß = 92.515(6)°, R1 = 0.0297 (I>2σ(I)). The crystal structure contains Li+ sandwiched by two 12-crown-4-ethers plus Li+ coordinated by one 12-crown-4- ether and one water molecule.[Li(15-crown-5)2(OH2)]3[Nb6Cl18]: space group R3̅, Z = 3, a = b = 2081.7(1), c = 1991.7(1) pm, R1 = 0.0395 (I > 2σ(I)). In the crystal structure Li+ and one water molecule are sandwiched by two 15-crown-5-ethers.[(18-crown-6)2(O2H5)]3[Nb6Cl18]: space group P1̅, Z = 1 ,a = 1405.1(1), b = 1461.1(2), c = 1492.2(2) pm; α = 98.80(1)°, ß = 98.15(1)°, γ = 97.41(1)°, R1 = 0.0538 (I > 2σ(I)). H5O2+ was found in the structure refinement sandwiched between two 18-crown-6-ethers.All compounds reported contain [Nb6Cl18] clusters with Nb-Nb distances between 299 and 301 pm. The paramagnetic behaviour expected for [Nb6Cl18]3- in all three compounds was confirmed by magnetic measurements.

ChemInform Abstract: Crystal Structure and Magnetic Ordering in ErFe6Ge6 Studied by X-Ray, Neutron Diffraction and Magnetic Measurements.

ChemInform ◽  
2010 ◽  
Vol 28 (48) ◽  
pp. no-no
Author(s):  
O. OLEKSYN ◽  
P. SCHOBINGER-PAPAMANTELLOS ◽  
J. RODRIGUEZ-CARVAJAL ◽  
E. BRUECK ◽  
K. H. J. BUSCHOW
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Magnetic Measurements ◽  
Magnetic Ordering ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document