Physics and Chemistry of Glasses最新文献

筛选

英文中文

Structural characterisation of rare earth rich glasses for nuclear waste immobilisation 核废料固定化用富稀土玻璃的结构表征

Physics and Chemistry of Glasses Pub Date : 2003-01-01 DOI: 10.1557/PROC-807-157

I. Bardez, D. Caurant, P. Loiseau, N. Baffier, J. Dussossoy, C. Gervais, F. Ribot, D. Neuville

{"title":"Structural characterisation of rare earth rich glasses for nuclear waste immobilisation","authors":"I. Bardez, D. Caurant, P. Loiseau, N. Baffier, J. Dussossoy, C. Gervais, F. Ribot, D. Neuville","doi":"10.1557/PROC-807-157","DOIUrl":"https://doi.org/10.1557/PROC-807-157","url":null,"abstract":"Local environments of rare earth ions are studied in a rare earth rich glass (Glass A wt%: 51.0SiO 2 -8.5B 2 O 3 -12.2Na 2 O-4.3Al 2 O 3 -4.8CaO-3.2ZrO 2 -16.0RE 2 O 3 with RE=Nd or La) developed for radioactive waste immobilisation. The aim is to determine the structural environment of rare earths in this glass according to their concentrations, and to study the influence of the peralkaline or peraluminous character of the glass on these environments. To achieve this objective, two series of glasses were prepared from Glass A. The first one contains variable amounts of rare earth oxide (from 0 to 30 wt% RE 2 O 3 ) and the second one is a series of peralkaline (R>50%) and peraluminous (R<50%) glasses, with R=([Na 2 O]+[CaO])/([Na 2 O]+[CaO] +[Al 2 O 3 ]) at fixed RE 2 O 3 contents (16 wt%). The coupling of characterisation methods such as EXAFS (extended x-ray absorption fine structure) spectroscopy at the neodymium L I I I -edge, optical absorption spectroscopy, Raman spectroscopy and 1 1 B, 2 9 Si and 2 7 Al MAS-NMR, enables discussion of several hypotheses concerning both the nature of rare earth neighbourhoods and the glassy network structure.","PeriodicalId":20166,"journal":{"name":"Physics and Chemistry of Glasses","volume":"45 1","pages":"320-329"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89342549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 38

EPR and optical absorption studies on Fe3+ ions in alkali borotellurite glasses 碱性硼碲酸盐玻璃中Fe3+离子的EPR和光学吸收研究

Physics and Chemistry of Glasses Pub Date : 2002-03-10 DOI: 10.1142/S0217984902003634

P. Prakash, A. Murali, J. Rao

{"title":"EPR and optical absorption studies on Fe3+ ions in alkali borotellurite glasses","authors":"P. Prakash, A. Murali, J. Rao","doi":"10.1142/S0217984902003634","DOIUrl":"https://doi.org/10.1142/S0217984902003634","url":null,"abstract":"Electron paramagnetic resonance and optical absorption spectra of Fe 3+ ions in 85M 2 B 4 O 7 . (15-x)TeO 2 , xFe 2 O 3 [(M=Li, Na or K); 0.5≤x≤10 mol%] glass systems have been studied. The EPR spectra of all glasses exhibit three resonance signals at g=2.0, g=4.2 and g=6.4. EPR spectra of 3 mol% Fe 2 O 3 doped lithium borotellurite glass system were studied at various temperatures. The intensity of the resonance signals decreases with increase in temperature whereas linewidths are found to be independent of temperature. EPR spectra exhibit a marked concentration dependence on iron content. A decrease in intensity for the resonance signal at g=4.2 with increase in iron content for more than 3 mol% has been observed and this has been attributed to the formation of clusters in the glass samples. The paramagnetic susceptibility was calculated from the EPR data at various temperatures and the Curie constant was calculated from the 1/X versus T graph. The optical absorption spectrum exhibits five bands characteristic of Fe 3+ ions in a distorted octahedral symmetry. From the observed band positions, the crystal field parameter, Dq. and the Racah interelectronic repulsion parameters, B and C, have been evaluated. The optical band gap energy was found to decrease with increase in iron content which indicates that the nature of the glasses become more semiconducting with increase of iron content.","PeriodicalId":20166,"journal":{"name":"Physics and Chemistry of Glasses","volume":"18 1","pages":"102-107"},"PeriodicalIF":0.0,"publicationDate":"2002-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81990407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25