Naslov
Studies of lead-iron phosphate glasses by Raman, Mossbauer and Impedance Spectroscopy

Autori
Moguš-Milanković, Andrea ; Šantić, Ana ; Furić, Krešimir ; Reis, Signo T. ; Day, Delbert E. ;

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts of the Glass&Optical Materials Meeting, The American Ceramics Society / M. Affatigato - Lahti : The American Ceramic Society, 2003

Skup
Glass and Optical Materials Division Fall Meeting 2003

Mjesto i datum
Corning (NY), Sjedinjene Američke Države, 12.10.2003. - 15.10.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Phosphate glasses; electrical conductivity; impedance spectra

Sažetak
The effect of Fe2O3 content on conductivity and glass stability against crystallization in the glass system PbO-Fe2O3-P2O5 has been investigated using Raman, XRD, Mössbauer and impedance spectroscopy. Glasses of the molar composition (43.3-x)PbO-(13.7+x)Fe2O3-43P2O5, (0ŁxŁ30), were prepared by quenching melts in air. With increasing Fe2O3 content and O/P ratio there is corresponding reduction in the length of phosphate units and an increase in the Fe(II) ion concentration which causes a higher tendency for crystallization. Raman spectra of the glasses show that the interaction between Fe sites, which is essential for electronic hopping, strongly depends on the cross-linking of the glass network. The electronic conduction of these glasses depends not only on the Fe(II)/Fetot ratio, but also on easy pathways for electron hopping in a non-disrupted pyrophosphate network. The Raman spectra of crystallized compositions indicate a much lower degree of cross-linking since more non-bridging oxygen atoms are present in the network. Despite the significant increase in the Fe2O3 content and Fe(II) ion concentration, there is a considerable weakening in the interactions between Fe sites in crystalline compositions. The impedance spectra reveal a decrease in conductivity that is caused by poorly defined conduction pathways, which result from the disruption and inhomogeneity of the crystalline phases that are formed during melting.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA