New Magnetic Metallic Glasses with Reduced Metalloid Content

1981 ◽  
Vol 8 ◽  
Author(s):  
R. C. O'handley ◽  
N. J. Grant
Keyword(s):  
Amorphous Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Early Transition Metal ◽  
New Class ◽  
Class 1 ◽  
Diffraction Patterns ◽  
Late Transition ◽  
The Stability ◽  
Early Transition

ABSTRACTSeveral new magnetic amorphous alloys containing early transition metals (TE) and having reduced metalloid (M) content have been melt spun. Some properties of three examples of this new class, 1) Co80Nb14B6, 2) Co84Nb10B6, and 3) Fe81Nb5B14, are presented. The dominant late transition meta1 (TL) content assures an appreciable magnetic moment while the presence of an early transition metal significantly enhances the stability against crystallization. Crystallization temperatures are 1) 742K, 2) 698K, and 3) 762K for the three alloys, respectively. X-ray diffraction patterns show the materials to be amorphous and to exhibit a large-r correlation length (approximately 2.0 A) that is shorter than is typiclly observed in TL80M20 glasses containing more than one transition meta) species (approximately 2.3 − 2.5A). The coercivities of the glassy compositions range from 30 to 70 m0e.

scholarly journals Radial X‐Ray Diffraction Study of Superhard Early Transition Metal Dodecaborides under High Pressure

2019 ◽  
Vol 29 (22) ◽  
pp. 1900293 ◽  
Author(s):  
Jialin Lei ◽  
Georgiy Akopov ◽  
Michael T. Yeung ◽  
Jinyuan Yan ◽  
Richard B. Kaner ◽  
...  
Keyword(s):  
High Pressure ◽  
Transition Metal ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Early Transition Metal ◽  
Early Transition

Ab initio powder X-ray diffraction structural analysis of bispidine based 1D coordination polymers: insights into their guest responsive behaviour

2019 ◽  
Vol 48 (44) ◽  
pp. 16756-16763 ◽  
Author(s):  
Martina Lippi ◽  
Massimo Cametti ◽  
Javier Martí-Rujas
Keyword(s):  
Structural Analysis ◽  
Coordination Polymer ◽  
Ab Initio ◽  
Coordination Polymers ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Class ◽  
Structure Solution ◽  
Responsive Behavior ◽  
The Stability

The first ab initio synchrotron powder XRD structure solution of a desolvated 1D bispidine coordination polymer (CP) is reported, providing valuable insights into the stability, dynamic and guest responsive behavior of a new class of CPs.

scholarly journals Preparation of CoFe2O4/SiO2Nanocomposites at Low Temperatures Using Short Chain Diols

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Thomas Dippong ◽  
Erika Andrea Levei ◽  
Oana Cadar
Keyword(s):  
Low Temperatures ◽  
Sol Gel ◽  
Silica Matrix ◽  
Short Chain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanocrystallite Size ◽  
Methylene Groups ◽  
Diffraction Patterns ◽  
The Stability

The preparation of 70% CoFe2O4/30% SiO2(wt%) nanocomposites by sol-gel method using three short chain diols (1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol) as chelators was studied. The Fourier transformed infrared spectra and X-ray diffraction patterns were used to confirm the formation of nanocomposites. The X-ray diffraction analysis showed that the chain length of the carboxylates embedded in the silica matrix influences the formation of crystallized cobalt ferrite as single phase at low temperatures. The influence of the methylene groups number in the precursors and annealing temperature on the nanocrystallite size was revealed. The stability of the obtained compounds was determined by calculation of thermodynamic parameters.

The stability and screw sense of the α -helix in poly- β -benzyl-L-aspartate

1960 ◽  
Vol 259 (1296) ◽  
pp. 110-128 ◽  
Keyword(s):  
Optical Rotatory Dispersion ◽  
Molecular Models ◽  
X Ray Diffraction ◽  
X Ray ◽  
Left Handed ◽  
The Difference ◽  
Diffraction Patterns ◽  
The Stability ◽  
Α Helix ◽  
The Right

A number of polymers and copolymers containing β -benzyl-L-aspartate has been prepared and their optical rotatory dispersion in a variety of solvents has been measured. The results of these measurements together with studies of infra-red spectra, X-ray diffraction patterns, deuteration rates and molecular models lead to the following conclusions. (i) The α -helical form of poly- β -benzyl-L-aspartate is considerably less stable relative to the solvated randomly coiled form than that of poly- γ -benzyl-L-glutamate. (ii) The left-handed α -helix of poly- β -benzyl-L-aspartate is more stable than the right-handed one. (iii) The difference in stability between the two senses of α -helix is much less in the case of poly- β -benzyl-L-aspartate than in that of poly- γ -benzyl-L-glutamate or poly-L-alanine.

scholarly journals The growth of decagonal Al–Co–Ni single crystals as a function of chemical composition

1997 ◽  
Vol 12 (9) ◽  
pp. 2274-2280 ◽  
Author(s):  
B. Zhang ◽  
M. Estermann ◽  
W. Steurer
Keyword(s):  
Single Crystals ◽  
Structural Changes ◽  
Ternary Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decagonal Phase ◽  
Different Types ◽  
Diffraction Patterns ◽  
The Stability ◽  
Diagram Analysis

Decaprismatic single crystals taken from a series of alloys of nominal compositions within Al65–77Co3–22Ni3–22 have been studied by means of x-ray diffraction techniques. The substitution of Co by Ni in increasing amounts changes the (pseudo)decagonal diffraction patterns drastically and indicates structural changes which range from a single-crystalline approximant via orientationally ordered nanodomain structures and quasiperiodic phases with different types of ordering phenomena, to a basic decagonal phase. A quantum phase diagram analysis shows a clear separation of the stability regions of the ternary systems described in this study and other decagonal phases.

scholarly journals LiCrO2 Under Pressure: In-Situ Structural and Vibrational Studies

Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Alka Garg ◽  
Daniel Errandonea ◽  
Julio Pellicer-Porres ◽  
Domingo Martinez-Garcia ◽  
Swayam Kesari ◽  
...  
Keyword(s):  
Research Work ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Coefficients ◽  
Vibrational Studies ◽  
Diffraction Patterns ◽  
The Stability ◽  
Murnaghan Equation ◽  
Related Compounds

The high-pressure behaviour of LiCrO2, a compound isostructural to the battery compound LiCoO2, has been investigated by synchrotron-based angle-dispersive X-ray powder diffraction, Raman spectroscopy, and resistance measurements up to 41, 30, and 10 Gpa, respectively. The stability of the layered structured compound on a triangular lattice with R-3m space group is confirmed in all three measurements up to the highest pressure reached. The dependence of lattice parameters and unit-cell volume with pressure has been determined from the structural refinements of X-ray diffraction patterns that are used to extract the axial compressibilities and bulk modulus by means of Birch–Murnaghan equation-of-state fits. The pressure coefficients for the two Raman-active modes, A1g and Eg, and their mode-Grüneisen parameters are reported. The electrical resistance measurements indicate that pressure has little influence in the resistivity up to 10 GPa. The obtained results for the vibrational and structural properties of LiCrO2 under pressure are in line with the published results of the similar studies on the related compounds. Research work reported in this article contributes significantly to enhance the understanding on the structural and mechanical properties of LiCrO2 and related lithium compounds.

A rectorite-pyrophyllite-chlorite-illite assemblage in pelitic rocks from Colombia

Clay Minerals ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 425-434 ◽  
Author(s):  
B. Brattli
Keyword(s):  
Grain Size ◽  
Mixed Layer ◽  
Low Pressure ◽  
X Ray Diffraction ◽  
Illite Crystallinity ◽  
X Ray ◽  
Diffraction Patterns ◽  
The Stability ◽  
Pelitic Rocks

AbstractIn samples of slate from the Fomeque Formation near Bogota, Colombia, pyrophyllite was found to occur together with mixed-layered illite-smectite, chlorite and illite. Other minerals were quartz, K-feldspar, dolomite and pyrite. X-ray diffraction patterns revealed that the mixed-layer represents an R1 ordered rectorite with 80–90% illite layers. The microfabric is developed as a closely spaced cleavage in the phyllosilicate-rich rocks, and grades into a fracture cleavage with coarsening of the grain size. No cleavage was observed in the interbedded siltstones. It is suggested that the microfrabrics developed in these rocks correspond to high diagenetic to anchizonal conditions. The illite crystallinity from the slate has been measured on glycolated samples and ranges from 0.47 to 0.55°Δ2θ with a mean of 0.52°Δ2θ Based on the stability of R1 ordered rectorite, the illite crystallinity and the microfabric development, it is proposed that the rocks have been subjected to a temperature of ∼200°C at low pressure. At this temperature, pyrophyllite can only be stabilized at the expense of kaolinite and quartz if aH2O ≪ 1.

Phase assignment to diffraction patterns based on the analytic properties of scattered fields applied to the structure of nerve myelin

1981 ◽  
Vol 14 (6) ◽  
pp. 455-461 ◽  
Author(s):  
R. E. Burge ◽  
M. A. Fiddy
Keyword(s):  
Experimental Error ◽  
Real Data ◽  
X Ray Diffraction ◽  
Distribution Of Zeros ◽  
Finite Fourier Transform ◽  
X Ray ◽  
Strong Measure ◽  
Diffraction Patterns ◽  
The Stability ◽  
Scattered Fields

An analysis of published X-ray diffraction data from nerve myelin is given based on the properties of analytic functions. Functions defined by a finite Fourier transform may be described by their distribution of zeros. This description allows a phase function to be determined from real data, which is unique in principle. A solution to the phase assignment is given and compared with corresponding published solutions derived by other methods. The strong measure of agreement for the phases of the first nine diffraction orders, and the stability of this agreement against the efforts of experimental error, leads to the conclusion that these phases are probably correct.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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