부산대학교 도서관

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1551-2916.2009.03095.x Byline: Mohsen Mahmoudysepehr (1), Vahak K. Marghussian (1) Abstract: Zirconolite [(CaZrTi.sub.2]O.sub.7) is a mineral that has a high containment capacity for actinides and lanthanides and is considered to be a good candidate for the immobilization of radioactive wastes. The glass-ceramic technique seems to be a very suitable and convenient method to produce zirconolite crystals by precipitating them in a specific glass matrix. In this study, development of a new zirconolite-based glass-ceramic belonging to SiO.sub.2-PbO-CaO-ZrO.sub.2-TiO.sub.2-([B.sub.2]O.sub.3-[K.sub.2]O) system was investigated. The presence of PbO, together with [B.sub.2]O.sub.3 and [K.sub.2]O, allowed the preparation of a X-ray diffraction (XRD) amorphous glass with a relatively high concentration of ZrO.sub.2 and TiO.sub.2, which was successfully converted to a glass-ceramic containing 34 wt% of zirconolite after heating at 770[degrees]C for 4 h. Differential thermal analysis, XRD, scanning electron microscope, and energy dispersive X-ray spectroscopy were used to determine the crystallization conditions, identify the crystallized phases, determine their compositions and quantities and observe and analyze the microstructures. The zirconolite crystals showed a platelet morphology with a monoclinic structure characterized by a=1.246 nm, b=0.7193 nm, c=1.128 nm, and [beta]=100.508[degrees]. Author Affiliation: (1)Ceramic Department, School of Materials, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran Article History: Manuscript No. 25636. Received December 14, 2008; approved March 14, 2009. Article note: [dagger]Author to whom correspondence should be addressed. e-mail: mahmoudysepehr@iust.ac.ir