Contribuicao ao estudo de uma metodologia alternativa para obtencao de dioxissulfeto de terras raras



Document title: Contribuicao ao estudo de uma metodologia alternativa para obtencao de dioxissulfeto de terras raras
Journal: Quimica nova
Database: PERIÓDICA
System number: 000196204
ISSN: 0100-4042
Authors: 1


Institutions: 1Universidade Federal da Paraiba, Departamento de Quimica, Joao Pessoa, Paraiba. Brasil
2Universidade de Sao Paulo, Instituto de Quimica, Sao Paulo. Brasil
Year:
Season: May-Jun
Volumen: 24
Number: 3
Pages: 320-323
Country: Brasil
Language: Portugués
Document type: Artículo
Approach: Experimental, descriptivo
English abstract In the last decade, many method has been developed to obtain oxysufides. However, theses materials were obtained by reaction involved gaseous toxics, CO, CS2, H2S and S. In the present work, the synthesis of lanthanum oxysufides actived by europium (III) through an alternative method has been made. This method involve the rare earth sulfate reduction under an atmosphere of argon contained 10% hydrogen using the thermogravimetric technique. The results showed the formation of the phase TR2O2S (TR = La and Eu) at temperatures which depend upon the heating rate, respectively 650 - 830ºC at 5ºC min-1 and 680 - 800ºC at 10ºC min-1. The oxysufides obtained are characterized by infrared spectroscopy. The method developed is more economic than the usual industrial methods and the environmental problems during the synthesis are also better controled
Disciplines: Química
Keyword: Química inorgánica,
Tierras raras,
Oxisulfuros,
Termogravimetría,
Gravimetría,
Descomposición térmica,
Europio,
Lantano
Keyword: Chemistry,
Inorganic chemistry,
Rare earths,
Oxysulfides,
Thermogravimetry,
Gravimetry,
Thermal decomposition,
Europium,
Lanthanum
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