Alternative approaches used to assess structural changes of natural zircon caused by heat treatment
| Autor: | P.D. Thang, L.T.T. Huong, N.T.M. Thuyet, N. Tran, The-Long Phan, B.T. Huy, D.N. Toan |
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| Rok vydání: | 2018 |
| Předmět: |
Diffraction
Photoluminescence Materials science Thermal decomposition Analytical chemistry 02 engineering and technology Crystal structure 010502 geochemistry & geophysics 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials symbols.namesake Paramagnetism Impurity symbols Electrical and Electronic Engineering 0210 nano-technology Raman spectroscopy 0105 earth and related environmental sciences Zircon |
| Zdroj: | Physica B: Condensed Matter. 532:42-47 |
| ISSN: | 0921-4526 |
| Popis: | It is known that large changes in the crystal structure of zircon (ZrSiO 4 ) can be assessed through the linewidth of the characteristic Raman mode (Δ ν 3 ) at 1008 cm −1 . However, the use of Δν 3 to assess small changes caused by heat treatment at temperatures below its decomposition temperature of ~1670 °C is difficult. The present work points out that the combination of X-ray diffraction (XRD) analyses, and photoluminescence (PL) and Raman (RS) measurements with different excitation wavelengths is an effective approach to solve the above problem. In this context, we have selected natural zircon containing some rare-earth (RE) impurities, and then studied the changes in its crystal structure caused by heat treatment at temperatures T an =400–1600 °C. XRD analyses reveal that small modifications of the unit-cell parameters occur as T an >600 °C. Taking the intensity ratios of the ν 3 mode to RE-related emissions ( I ν 3 / I RE ) or the PL intensity ratios between RE-related emissions into consideration, the similar results in good agreement with the XRD analyses are also found. We believe that the small structural changes are related to the migration and redistribution of defects and impurities, and re-crystallization of zircon. This could be further confirmed though the relation between paramagnetic and ferromagnetic signals when T an changes. |
| Databáze: | OpenAIRE |
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