RTU Research Information System
Latviešu English

Publikācija: Phase Transition in Niobophosphate Glass-Ceramic

Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Phase Transition in Niobophosphate Glass-Ceramic
Field of research 2. Engineering and technology
Sub-field of research 2.5 Materials engineering
Research platform None
Authors Agnese Stunda Zujeva
Ņina Mironova-Ulmane
Natālija Borodajenko
Līga Bērziņa-Cimdiņa
Keywords glass, crystalliztion, phosphate, niobate
Abstract Abstract: Phase transition during crystallization of glass to glass-ceramic in system P2O5-CaO-Nb2O5-Na2O was studied. Several heating rates were compared – 1, 2, 5, 11 and 20°Cmin-1. DTA, XRD, FTIR and Raman analyses were performed. Niobophosphate glass-ceramic is found to form utterly different crystalline phases depending on maximal heating temperature, heating rate and time of maximal temperature maintenance. Crystallization temperatures of the same phases are strongly dependent on heating rate, while crystallinity of obtained phases is not. At lower temperatures poorly crystalline phosphates (Ca3(PO4)2, Ca10Na(PO4)7, Ca2P2O7) and niobates (NaNbO3 and Nb2O5) are identified. At higher temperatures a large amount of well crystalline niobophosphate (Na4(Nb8P4O32) and Ca2P2O7 forms. With increasing amount of Na4(Nb8P4O32), amount of NaNbO3 and Nb2O5 decreases. Phase transition during crystallization of glass to glass-ceramic in system P2O5-CaO-Nb2O5-Na2O was studied. Several heating rates were compared – 1, 2, 5, 11 and 20ºCmin-1. DTA, XRD, FTIR and Raman analyses were performed. Niobophosphate glass-ceramic is found to form utterly different crystalline phases depending on maximal heating temperature, heating rate and time of maximal temperature maintenance. Crystallization temperatures of the same phases are strongly dependent on heating rate, while crystallinity of obtained phases is not. At lower temperatures poorly crystalline phosphates (Ca3(PO4)2, Ca10Na(PO4)7, Ca2P2O7) and niobates (NaNbO3 and Nb2O5) are identified. At higher temperatures a large amount of well crystalline niobophosphate (Na4(Nb8P4O32) and Ca2P2O7 forms. With increasing amount of Na4(Nb8P4O32), amount of NaNbO3 and Nb2O5 decreases.
DOI: 10.4028/www.scientific.net/AMR.222.259
Hyperlink: http://www.scientific.net/AMR.222.259 
Reference Stunda Zujeva, A., Mironova-Ulmane, Ņ., Borodajenko, N., Bērziņa-Cimdiņa, L. Phase Transition in Niobophosphate Glass-Ceramic. Advanced Material Research, 2011, Vol. 222, pp.259-262. ISSN 1022-6680. Available from: doi:10.4028/www.scientific.net/AMR.222.259
Additional information Citation count:
ID 8012