Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 3
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

In the article, the characterization of the microstructure, phase composition and distribution of elements in the Eu2O3-ZrO2 sintered materials obtained by four different ways of powders’ homogenization (mixing) process and different temperature of sintering process is shown. The feedstock powders with an average mole ratio of ZrO2 to Eu2O3 equal 74% to 26% were used as an initial material. The principal aim of the investigation was characterization of differences in the microstructure of the same type of ceramics, however, prepared via different mixing and manufacturing processes. The range of the investigation covered a characterization of these materials via phase identification of all samples by XRD (X-ray diffraction) and characterization of internal morphology of the specimens with detailed analysis of elements distributions by SEM (scanning electron microscopy) and EDS (energy dispersive spectrometry). The aim of the following investigation is to characterize the possibilities of the solid state synthesis of the europium zirconate based materials, dedicated for TBC applications.

Go to article

Authors and Affiliations

M. Mikuśkiewicz
G. Moskal
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

Neoproterozoic ( c. 640 Ma) amphibolite facies metamorphism and deformation have been shown recently to have affected the Isbj ø rnhamna and Eimfjellet Complex of Wedel Jarlsberg Land in southwestern Spitsbergen. New SHRIMP zircon U−Pb and in situ electron microprobe monazite and uraninite U−Th−total Pb ages are presented here on a pegmatite occurring within the Isbj ø rnhamna metasedimentary rocks. Although the dated zircons are full of inclusions, have high−U contents and are metamict and hence have experienced notable Pb−loss, the new Cryogenian ages are consistent with the age of regional metamorphism of the host metasediments, providing additional evidence for a clear distinction of the Southwestern Province from the other parts of the Svalbard Caledonides.
Go to article

Authors and Affiliations

Jarosław Majka
Alexander N. Larionov
David G. Gee
Jerzy Czerny
Jaroslav Pršek
Download PDF Download RIS Download Bibtex

Abstract

Compositional and textural data are presented for zircon, secondary Zr-silicates, catapleiite and elpidite in a peralkaline granite from the Ilímaussaq complex, south Greenland. The zircon is essentially stoichiometric, with (Zr + Hf + Si) = 1.96–1.98 a.p.f.u. The secondary Zr-silicates show a wide range of Zr/Si atomic ratios (0.13–0.79). The catapleiite varies from close to stoichiometric to a Na-depleted type showing cation deficiency (5.2–5.8 a.p.f.u.). Elpidite shows similar variations (7.2–9.0 a.p.f.u.). Textural relationships between the Zr phases are interpreted to show that magmatic zircon interacted with hydrous fluids exsolved from the magma to form the secondary Zr-silicates. Formation of catapleiite was late‑magmatic, in equilibrium with a Na-Sibearing fluid. This was followed by the crystallization of elpidite, the fluid having a different Na/Si ratio. Both catapleiite and elpidite experienced Na-loss during late-stage hydrothermal alteration.
Go to article

Authors and Affiliations

Małgorzata Cegiełka
1 2
Bogusław Bagiński
1
Ray Macdonald
1 3
Harvey E. Belkin
4
Jakub Kotowski
1
Brian G.J. Upton
5

  1. Department of Geochemistry, Mineralogy and Petrology, Faculty of Geology, University of Warsaw, ul. Żwirki i Wigury 93, 02-089 Warsaw, Poland
  2. Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Warsaw, ul. Twarda 51/55, 00-818 Warsaw, Poland
  3. Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
  4. 11142 Forest Edge Drive, Reston, VA 20190, USA
  5. Grant Institute, University of Edinburgh, James Hutton Rd., Edinburgh EH9 3FE, UK

This page uses 'cookies'. Learn more