X-ray diffraction studies of phase transformations in heavy-metal fluoride glasses

1985 ◽  
Vol 20 (8) ◽  
pp. 2794-2800 ◽  
Author(s):  
Narottam P. Bansal ◽  
Robert H. Doremus
1992 ◽  
Vol 7 (6) ◽  
pp. 1534-1540 ◽  
Author(s):  
A.M. Mailhot ◽  
A. Elyamani ◽  
R.E. Riman

A glass based on ZrF4 was synthesized by a combination of sol-gel and reactive atmosphere processing. Infrared spectroscopy and combustion analysis show that the fluorination process reduces the concentration of organic and hydroxide impurities. Chemical changes have occurred during fluorination; this is indicated by different x-ray diffraction traces and crystallization characteristics for the fluorinated sample compared to the oxide gel product. Chemical analysis from x-ray fluorescence indicates that the fluorinated gel is chemically similar to a melted glass of the same composition. Differential scanning calorimetry gives a glass transition temperature of 290 °C and a crystallization temperature of 390 °C. These values are consistent with those expected for a fluoride glass prepared by conventional methods.


1995 ◽  
Vol 417 ◽  
Author(s):  
L. Niu ◽  
A. R. Kortan ◽  
N. Kopylov ◽  
P. H. Citrin

AbstractNear-edge and extended x-ray absorption fine structure (NEXAFS and EXAFS) measurements have been made as a function of Pb dopant concentration to study the changes in local geometric and electronic structure in several heavy-metal fluoride glasses (Zr/Ba/La/Al/Na, or ZBLAN). A strong correlation is found between the observed glass instability for Pb concentrations > 10% and the structural changes that are measured exclusively around the Ba atoms. Implications of these novel findings are examined in light of the present understanding of these complex glass systems.


1984 ◽  
Author(s):  
Jacques Lucas ◽  
Denis Tregoat ◽  
Ahmed El Houari ◽  
Gilles Fonteneau

1997 ◽  
Vol 213-214 ◽  
pp. 95-100 ◽  
Author(s):  
J.C. Fajardo ◽  
G.H. Sigel ◽  
B.C. Edwards ◽  
R.I. Epstein ◽  
T.R. Gosnell ◽  
...  

1986 ◽  
Vol 22 (3) ◽  
pp. 117 ◽  
Author(s):  
D.C. Tran ◽  
K.H. Levin ◽  
R.J. Ginther ◽  
G.H. Sigel ◽  
A.J. Bruce

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