Structural features of thin layers of zirconium dioxide by IR spectroscopy

1983 ◽  
Vol 39 (2) ◽  
pp. 929-933 ◽  
Author(s):  
I. I. Shaganov ◽  
�. I. Fadeeva ◽  
E. N. Eliseev ◽  
O. P. Ankudinova
Keyword(s):  
Ir Spectroscopy ◽  
Zirconium Dioxide ◽  
Structural Features ◽  
Thin Layers

Structural features of the vesicle of Frankia sp. CpI1 in culture

1982 ◽  
Vol 28 (7) ◽  
pp. 749-757 ◽  
Author(s):  
John G. Torrey ◽  
Dale Callaham
Keyword(s):  
Electron Microscopy ◽  
Symbiotic Nitrogen Fixation ◽  
Polarized Light ◽  
Structural Features ◽  
Thin Layers ◽  
Structural Studies ◽  
Filamentous Bacterium ◽  
Cyanobacterium Anabaena ◽  
Laminated Layer ◽  
Synthetic Nutrient Medium

The filamentous bacterium Frankia sp. CpI1 of the Actinomycetales, responsible for symbiotic nitrogen fixation in the nodules of certain woody dicots, also fixes dinitrogen when grown independently of the host in a nitrogen-free synthetic nutrient medium under aerobic conditions. In structural studies of Frankia grown in culture it has been shown that the bacterial filaments form vesicles, enlarged terminal endings in which the enzyme nitrogenase is formed. Microscopic examination of cultures shows that the vesicles possess a specialized envelope consisting of a number of thin layers or laminae which in polarized light show birefringence and in freeze-etch electron microscopy are resolved as multiple (12–15) laminae approximately 35–40 Å (1 Å = 0.1 nm) in thickness. Comparisons are made between the structure of the vesicle envelope in cultured Frankia and the strikingly similar innermost laminated layer in the dinitrogen-fixing heterocysts of the cyanobacterium Anabaena. Comparable protective functions in limiting oxygen to the dinitrogen-fixing sites are suggested for these similar structures in two quite unrelated microorganisms.

Vibrational Studies of Zinc Antimony Borophosphate Glasses Doped Rare Earth

2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Aliff Rohaizad ◽  
Rosli Hussin ◽  
Nur Aimi Syaqilah Aziz ◽  
Royston Uning ◽  
Nur Zu Ira Bohari
Keyword(s):  
Rare Earth ◽  
Ir Spectroscopy ◽  
Structural Features ◽  
Phase Changes ◽  
Hydroxyl Group ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Borophosphate Glasses ◽  
Compositional Changes ◽  
Composition Changes

Zinc antimony borophosphate glasses has been determined for [10P2O5 –40B2O3 –xSb2O3 –(50–x)ZnO] and composition of [10P2O5 – 40B2O3 –40Sb2O3 –10ZnO] has been doped with 1 mol% of rare earth (Eu, Nd, Sm, Er). The functions of compositional changes on their structural features were examined using X–Ray Diffraction (XRD) to detect the amorphousity phase present. While Fourier Transform Infrared (IR) Spectroscopy were used to identify the presences of vibrational modes and band assignments of phosphate, borate, antimony, zinc and Rare earth ion in the system. XRD results expose that crystalline phase changes with different amount of zinc and antimony substitution. Hydroxyl group absorption also vary due to this composition changes and clearly shown in IR spectroscopy in the ranges 1400–4000 cm–1. Result of IR spectroscopy indicated that bands around 1440 cm–1 and 760 cm–1 was ascribed to the vas(B–O–B) and vs(P–O–P) vibration respectively. The changes of this vibration indicated that P–O–B linkage was formed near 660 cm–1. The modification of zinc antimony borophosphate glasses with rare earth was studied and showed present of rare earth ion in the glass system does not change the structural features.

Analysis of Structural Features of Humic Acids Fractions after Mechanochemical Modification

2015 ◽  
Vol 1085 ◽  
pp. 3-6 ◽  
Author(s):  
Malika P. Mirzobekzoda ◽  
Elizaveta V. Maltseva ◽  
Natalya S. Shekhovtsova
Keyword(s):  
Chemical Composition ◽  
Ir Spectroscopy ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Structural Features ◽  
Acid Base ◽  
Structural Composition ◽  
Mechanochemical Modification ◽  
The Impact ◽  
First Time

Humic substances are the major components of soil, peat and brown coal. They can be fractionating into fulvic acids (FA), brown humic acids (BHA) and gray humic acids (GHA). In this work we investigated the influence of mechanochemical modifications on structural composition of HAs main fractions using the methods of IR and 1H MRS spectroscopy. The IR spectroscopy results has shown that HA has different chemical composition in comparison with GHA and BHA. Potentiometric titration showed that mechanoactivation (MA) with thiourea increases the amount of oxygen-containing groups up to 2.5. For the first time we studied the impact of modifying agent of thiourea on the structural composition and acid-base properties of HAs major fractions - GHA and BHA during the mechanoactivation process.

Studying the local structural features of Zn2 − 2x Cd2x V2O7 by NMR and IR spectroscopy

2012 ◽  
Vol 76 (3) ◽  
pp. 371-373 ◽  
Author(s):  
T. I. Krasnenko ◽  
N. A. Zhuravlev ◽  
L. A. Perelyaeva
Keyword(s):  
Ir Spectroscopy ◽  
Structural Features

Zirconium difluoride

1964 ◽  
Vol 17 (7) ◽  
pp. 727 ◽  
Author(s):  
FK McTaggart ◽  
AG Turnbull
Keyword(s):  
Atomic Hydrogen ◽  
Zirconium Dioxide ◽  
Chemical Properties ◽  
Thin Layers ◽  
Zirconium Tetrafluoride ◽  
Group Iva

Zirconium difluoride was prepared by the action of atomic hydrogen on thin layers of zirconium tetrafluoride, at a temperature of approximately 350�. The compound is orthorhombic in structure. It is black, tends to take up oxygen in air, and ignites readily and burns to form zirconium dioxide. Disproportionation occurs at 800� with the formation of ZrF4 and zirconium, and other chemical properties are similar to those of the known dihalides of Group IVA.

scholarly journals Changes in the structure and properties of ZrO2 detonation coatings during annealing

2020 ◽  
Vol 4 (4) ◽  
pp. 319-326
Author(s):  
B.K. Rakhadilov ◽  
D.N. Kakimzhanov ◽  
G. Botabaeva ◽  
D.B. Buitkenov ◽  
N. Kantai ◽  
...  
Keyword(s):  
Zirconium Dioxide ◽  
Microscopic Analysis ◽  
Thin Layers ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Detonation Spraying ◽  
Electron Microscopic ◽  
Before And After ◽  
New Generation ◽  
High Adhesive Strength

The article studied the effect of annealing on the structure and properties of zirconium dioxide coatings obtained by detonation spraying. Detonation spraying was realized on a computerized detonation spraying complex of the new generation CCDS2000. Determined that coatings made of zirconium dioxide are characterized by high adhesive strength of adherence to the substrate. Thermal annealing of coated samples was performed at temperatures of 900-1200◦ C. It was determined that the microhardness of zirconium dioxide coatings increases by 10-25% depending on the annealing temperature after annealing. The results of nanoindentation showed that the nanohardness of the coatings after annealing at 1000◦ C increases by 50%. It was determined that after annealing at 1000◦ C, the elastic modulus of the coatings increases, which indicates a decrease in plasticity and an increase in the strength of the coatings. X-ray diffraction analysis showed that the phase composition of coatings before and after annealing consists of t-ZrO2. After annealing occurs there is an increase in the degree of t-ZrO2 tetragonality. Electron microscopic analysis showed that an increase in the number and size of micro-continuity in the form of thin layers after annealing. Determined that increase the hardness of zirconium dioxide after annealing at 900-1200◦ C is associated with a higher degree of tetragonality t-ZrO2 phase.

Azide und Cyanamide – ähnlich und doch anders/Azides and Cyanamides – Similar and Yet Different

2003 ◽  
Vol 58 (11) ◽  
pp. 1097-1104 ◽  
Author(s):  
Olaf Reckeweg ◽  
Arndt Simon
Keyword(s):  
Ir Spectroscopy ◽  
Single Crystals ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Structural Features ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time ◽  
Raman And Ir Spectroscopy

Abstract The crystal structures of LiN3*H2O (P63/mcm (No. 193), Z = 6; 924.01(13); 560.06(7) pm); NH4N3 (Pmna (No. 53), Z =4; a=889.78(18), b=380,67(8), c=867.35(17) pm); Ca(N3)2 (Fddd (No. 70), Z = 8; a=595.4(2), b=1103.6(5), c=1133.1(6) pm), Sr(N3)2 (Fddd (No. 70), Z =8; a= 612.02(9), b = 1154.60(18), c = 1182.62(15) pm); Ba(N3)2 (P21/m (No. 11), Z = 2; a = 544.8(1), b = 439.9(1), c = 961.3(2) pm, β = 99.64(3)°) and TlN3 (I4/mcm (No. 140), Z = 2; 618.96(9); 732.71(15) pm) have been either determined for the first time or redetermined by X-ray diffraction on single crystals. The afore mentioned compounds, AN3 (A = Na, K, Rb, Cs), M(N3)2 · 2.5 H2O (M = Mg, Zn) and the cyanamides Li2CN2, CdCN2 and CuCN2 were investigated by Raman and IR spectroscopy (KBr technique). Structural features and spectroscopic data of azides and cyanamides from this work and from literature are listed and compared.

scholarly journals Silicon-Oxygen Region Infrared and Raman Analysis of Opals: The Effect of Sample Preparation and Measurement Type

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Neville J. Curtis ◽  
Jason R. Gascooke ◽  
Allan Pring
Keyword(s):  
Ir Spectroscopy ◽  
High Refractive Index ◽  
Structural Features ◽  
Longitudinal Optical ◽  
Attenuated Total Reflection ◽  
Silica Glasses ◽  
Specular Reflectance ◽  
Primary Means ◽  
Infrared Wavelengths ◽  
Non Destructive

An extensive infrared (IR) spectroscopy study using transmission, specular and diffuse reflectance, and attenuated total reflection (ATR) was undertaken to characterise opal-AG, opal-AN (hyalite), opal-CT and opal-C, focussing on the Si-O fingerprint region (200–1600 cm−1). We show that IR spectroscopy is a viable alternative to X-ray powder diffraction (XRD) as a primary means of classification of opals even when minor levels of impurities are present. Variable angle specular reflectance spectroscopy shows that the three major IR bands of opal are split into transverse optical (TO) and longitudinal optical (LO) components. Previously observed variability in powder ATR is probably linked to the very high refractive index of opals at infrared wavelengths, rather than heterogeneity or particle size effects. An alternative use of ATR using unpowdered samples provides a potential means of non-destructive delineation of play of colour opals into opal-AG or opal-CT gems. We find that there are no special structural features in the infrared spectrum that differentiate opal from silica glasses. Evidence is presented that suggests silanol environments may be responsible for the structural differences between opal-AG, opal-AN and other forms of opaline silica. Complementary studies with Raman spectroscopy, XRD and scanning electron microscopy (SEM) provide evidence of structural trends within the opal-CT type.

Application of IR-Spectroscopy for Study of Alumosilicate Raw Materials

2014 ◽  
Vol 496-500 ◽  
pp. 96-101 ◽  
Author(s):  
Mikhail Sergeevich Lebedev ◽  
Igor Vladimirovich Zhernovsky ◽  
Valeria Valerievna Strokova ◽  
Ekaterina Viktorovna Fomina ◽  
Natalia Ivanovna Kozhukhova
Keyword(s):  
Composite Materials ◽  
Ir Spectroscopy ◽  
Material Science ◽  
Raw Materials ◽  
Construction Material ◽  
Structural Features ◽  
Analytic Method ◽  
Essential Tool

IR-spectroscopy is an essential tool for the study of the structural features of the material, regardless of its state (amorphous or crystalline). It allows accurately explain the type and character of structural bonds, the presence of certain molecular groups in the material. For the construction material science, this analytic method helps to study raw materials and composite materials, binders, etc.

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