Determination and estimation of magnesium content in the single phase magnesium-calcite [Ca(1−x)MgxCO3(s)] using electron probe micro-analysis (EPMA) and X-ray diffraction (XRD)

2018 ◽  
Vol 22 (2) ◽  
pp. 303-312 ◽  
Author(s):  
Muhammad Fahad ◽  
Sundas Saeed
Keyword(s):  
Electron Probe ◽  
Single Phase ◽  
Magnesium Content ◽  
Electron Probe Micro Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Calcite ◽  
Micro Analysis

scholarly journals The Polythermal Section of Ti-22Al-xNb (30-78at.%Ti) in Ti–Al–Nb System

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 871
Author(s):  
Yun Zhao ◽  
Li-Bin Liu ◽  
Li-Gang Zhang ◽  
Jia-Jun Yang ◽  
Patrick J. Masset
Keyword(s):  
Single Phase ◽  
Invariant Reaction ◽  
Polythermal Section ◽  
Electron Probe Micro Analysis ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Three Phase ◽  
Micro Analysis ◽  
O Phase

The polythermal section of Ti-22Al-xNb (30–78 at.% Ti) in the Ti-Al-Nb system was studied using X-ray diffraction analysis (XRD), differential thermal analysis (DSC), and electron probe micro-analysis (EPMA). No new ternary compounds were found in this work. The polythermal section has five three-phase regions, nine two-phase regions, and three single-phase regions. The O phase transition is confirmed to occur below 1000 °C. A four-phase invariant reaction β + σ → O + δ was found at 931 °C.

scholarly journals THE HIGH-MAGNESIUM CALCITE ORIGIN OF NUMMULITID FORAMINIFERA AND IMPLICATIONS FOR THE IDENTIFICATION OF CALCITE DIAGENESIS

Palaios ◽  
2020 ◽  
Vol 35 (10) ◽  
pp. 421-431
Author(s):  
LAURA J. COTTON ◽  
DAVID EVANS ◽  
SIMON J. BEAVINGTON-PENNEY
Keyword(s):  
Magnesium Content ◽  
Carbonate Diagenesis ◽  
X Ray Diffraction ◽  
Larger Benthic Foraminifera ◽  
X Ray ◽  
Low Magnesium ◽  
Fossil Material ◽  
Magnesium Calcite ◽  
High Magnesium Calcite ◽  
Geochemical Studies

ABSTRACT Nummulites were one of the most abundant and widespread larger benthic foraminifera of the Paleogene, however, confusion remains within the literature as to whether their original test mineralogy was high or low magnesium calcite. As the number of studies using proxies based on Nummulites and related nummulitid geochemistry increase, it is essential to have a firm understanding of test composition to assess preservation within potential samples, and to interpret results. Here we employ a combination of X-ray diffraction, Fourier transform infra-red spectroscopy, and laser ablation ICPMS to determine magnesium content across exceptionally preserved and poorly preserved fossil material as well as modern examples of nummulitids—showing conclusively a primary intermediate to high magnesium calcite composition. This composition appears to be closely related to fluctuating ocean chemistry through the Paleogene. Using these results as an indicator of preservation we examine variation in trace element data across a suite of samples, and introduce the concept of the preservagram, a method of quickly visualizing different styles of carbonate diagenesis. Understanding the original mineralogy of nummulitids and, therefore, the extent to which specimens have been diagenetically altered, is essential as larger foraminifera are increasingly used in geochemical studies.

Solvothermal Synthesis of α-Quartz Powder Doped with Germanium

2008 ◽  
Vol 63 (6) ◽  
pp. 739-741 ◽  
Author(s):  
Alain Largeteau ◽  
Stéphane Darracq ◽  
Graziella Goglio
Keyword(s):  
Solvothermal Synthesis ◽  
Electron Probe ◽  
Sol Gel ◽  
Experimental Investigations ◽  
Electron Probe Micro Analysis ◽  
Quartz Powder ◽  
X Ray ◽  
Cell Parameters ◽  
Micro Analysis ◽  
Solvothermal Conditions

Experimental investigations concerning the synthesis of Si1−xGexO2 solid solutions with quartz structure have been carried out under solvothermal conditions from sol-gel preparations. The cell parameters of the powders have been determined by X-ray powder diffraction. The amount of germanium inside the SiO2 structure was measured also by electron probe micro-analysis (EPMA).

A STUDY OF MACROCRYSTALLINE PEDOGENIC CARBONATES USING SUBMICROSCOPIC TECHNIQUES

1981 ◽  
Vol 61 (2) ◽  
pp. 261-272 ◽  
Author(s):  
A. R. MERMUT ◽  
R. J. ST. ARNAUD
Keyword(s):  
Electron Probe ◽  
Size Range ◽  
X Ray Diffraction ◽  
Pedogenic Carbonate ◽  
X Ray ◽  
Pedogenic Carbonates ◽  
Layered Crystals ◽  
Magnesium Calcite ◽  
Sem Analyses

Calcitic plasmic fabric, grain calcans, neocalcitans and carbonatic glaebules with diffuse boundary were studied in situ, in soils by electron probe and SEM analyses. The occurrence of pedogenic magnesium-bearing calcite, previously detected by a shift of X-ray diffraction spacing on bulk samples, was verified by electron probes analyses on purely pedogenic carbonatic sites. This made it possible to understand further the nature of carbonates and to differentiate pure calcite from magnesium-bearing calcite. Common types of microcrystalline pedogenic carbonates included elongated, equidimensional, rod-shaped, and layered crystals. Equidimensional crystals were common in calcite, whereas elongated and rod types occurring sometimes as bundles of coalescing fibres were found to be magnesium calcite. Most visible pedogenic carbonate crystals in the soils studies had a diameter of 0.3–1.0 μm. This size range may be important in establishing relative levels of secondary carbonates in soils. Phosphorus values for studied features were higher than in the entire soil and arc evidence of precipitation of this element with pedogenic carbonates.

The CaO-TiO2-ZrO2 System at 1200 °C and the Solubilities of Hf and Gd in Zirconolite

1995 ◽  
Vol 412 ◽  
Author(s):  
D. Swenson ◽  
T. G. Nieh ◽  
J. H. Fournelle
Keyword(s):  
Solid Solutions ◽  
Electron Probe ◽  
Single Phase ◽  
Stoichiometric Composition ◽  
Mutual Solubility ◽  
X Ray Diffraction ◽  
Constant Concentration ◽  
Experimental Conditions ◽  
X Ray ◽  
Zro2 System

AbstractPhase equilibria are established in the CaO-TiO2-ZrO2 system at 1200 °C, using X-ray diffraction and electron probe microanalysis. The existence of two previously reported ternary phases, zirconolite (CaZrTi2O7) and calzirtite (Ca2Zr5Ti2O16), is confirmed. Each of these phases exhibits a significant range of homogeneity between TiO2 and ZrO2 while maintaining a nearly constant concentration of CaO. The ternary solubilities of the constituent binary phases are found to be negligible, with the exceptions of the perovskites, which display mutual solubility of at least 22 mol.% and may in fact form a series of continuous solid solutions. The solubilities of Hf and Gd in zirconolite are also investigated. While Hf-bearing samples did not reach thermodynamic equilibrium under the experimental conditions employed, the existence of a Hf analog to zirconolite, CaHfTi2O7, is conclusively demonstrated. The phase is stable at the stoichiometric composition, and its lattice parameters are very close to those reported in the literature for stoichiometric zirconolite. A Gd-bearing sample of the composition Ca0.88Zr0.88Gd0.24Ti2O7 is found to be essentially single phase zirconolite, in agreement with previous investigations at higher temperatures.

scholarly journals Quantified X-Ray Mapping in the WDS Mode

2018 ◽  
Vol 925 ◽  
pp. 520-523
Author(s):  
Gunilla Runnsjö ◽  
Kaj Grönlund
Keyword(s):  
Spectral Resolution ◽  
Material Science ◽  
Electron Probe ◽  
High Spectral Resolution ◽  
Electron Probe Micro Analysis ◽  
X Ray ◽  
Wavelength Dispersive Spectrometry ◽  
Micro Analysis

In material science, there is an increased demand for mapping of microstructural components and their composition. EPMA (Electron Probe Micro Analysis) with WDS (Wavelength Dispersive Spectrometry) is known as having high spectral resolution and sensitivity, but in practice considered to be slow in mapping applications. The present work describes a development of EPMA including design of both instrumental hardware and software related to electronics and calibration.

Visualization and detectability of elements rarely contained in soft tissue by X-ray scanning analytical microscopy and electron-probe micro analysis

Biomaterials ◽  
2001 ◽  
Vol 22 (13) ◽  
pp. 1787-1794 ◽  
Author(s):  
Motohiro Uo ◽  
Fumio Watari ◽  
Atsuro Yokoyama ◽  
Hironobu Matsuno ◽  
Takao Kawasaki
Keyword(s):  
Soft Tissue ◽  
Electron Probe ◽  
Electron Probe Micro Analysis ◽  
X Ray ◽  
Analytical Microscopy ◽  
Micro Analysis

Enhancement in Curie Temperature with Magnesium Substituted in Sintered MgxMn1-xFe2O4 Pellets of Nanopowders

2016 ◽  
Vol 43 ◽  
pp. 38-45 ◽  
Author(s):  
Sohrab Manouchehri ◽  
Seyed Taghi Mohammadi Benehi ◽  
Mohammad Hassan Yousefi
Keyword(s):  
Curie Temperature ◽  
Lattice Constant ◽  
Single Phase ◽  
Lattice Models ◽  
Substitution Effect ◽  
Magnesium Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Trend ◽  
Single Phase Formation

Ferrites nanopowder of spinel MgxMn1-xFe2O4 (with x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) synthesized by the coprecipitation method and pellets of nanopowder sintered at temperature 1250 °C. The X-ray diffraction results confirmed the single phase formation of the samples. The lattice constant and interionic distances decreased with increase in magnesium content that can be originated by strengthening of A–B interaction. The substitution effect of nonmagnetic Mg2+ ions was studied on Curie temperature of sintered pellets. Curie temperature measurements exhibit increasing trend with increase in magnesium content. Enhancement in Curie temperature can be explained on the basis of strengthening of A–B interaction and Neel’s two sub-lattice models.

120 K SUPERCONDUCTOR TlBaCaCu2Oy

1988 ◽  
Vol 02 (01) ◽  
pp. 479-481 ◽  
Author(s):  
Z.X. ZHAO ◽  
L.Q. CHEN ◽  
Z.H. MAI ◽  
Y.Z. HUANG ◽  
Z.L. XIAO ◽  
...  
Keyword(s):  
Single Phase ◽  
Oxide System ◽  
Tetragonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edax Analysis ◽  
Micro Analysis ◽  
Single Phase Material

We have prepared 120 K superconductor in Tl-Ba-Ca-Cu oxide system. This 120 K superconductor has been investigated by x-ray diffraction and EDAX micro-analysis. EDAX analysis shows that the composition of this superconductor is very close to TlBa ( Ca 1−x Cu x) CuO y(x−0.3). Most of the x-ray powder diffractions including all the strong ones can be indexed according to a tetragonal structure with a=5.46 Å and c= 36.2 Å which means that the sample is nearly a single phase material.

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