Ordering of disordered materials occurs during the activated process of nucleation that requires the formation of critical clusters that have to surmount a thermodynamic barrier. The characterization of these clusters is experimentally challenging but mandatory to improve nucleation theory. In this paper, the nucleation of a magnesium alumino-silicate glass containing the nucleating oxide TiO(2...

Mineral compositions and reaction textures found in migmatitic gneisses from near Gilsum, New Hampshire, constrain both peak metamorphic pressure (P) and temperature (T) conditions and the PT path. Large K-feldspar porphyroblasts indicate isobaric heating of the samples at P < 4 kb (Spear et al. 1999), and relict cordierite + garnet assemblages record the occurrence of biotite vapor-absent melt...

Abstract The paper studied the synthesis of cordierite powders and preparation ultra-low thermal expansion ceramic with high elastic modulus. powder was synthesized by solid state reaction using MgO, Al 2 O 3 SiO as raw materials. effect temperature on purity, phase properties mainly studied. results show that higher purity reactivity at 1390°C, containing two kinds (α-cordierite β-cordierite)....

Kordiyerit esaslı cam-seramikler, yüksek termal direnç özellikleri ile birlikte düşük dielektrik sabiti ve genleşme katsayısına sahip mühendislik malzemeleridir. Düşük maliyetlerde üretilebilmesi iyi elektriksel özelliklere olması dolayısıyla, kordiyerit cam-seramikler elektronik endüstrisinde alümina yerine altlık malzeme olarak kullanılabilmekte ayrıca çok katmanlı devre kartlarının, kataliti...

This paper compares different coating methods (in situ solid combustion, hybrid deposition, secondary growth on seed, suspension, double deposition of wet impregnation and suspension) to deposit Ce0.2Zr0.8O₂ mixed oxides on cordierite substrates, for use as a three way catalyst. Among them, the double deposition was proven to be the most efficient one. The coated sample shows a BET (Brunauer-Em...

The formation of porphyroblasts by replacement and displacement of pre-existing S surfaces is examined in the light of textural evidence displayed by sediments hornfelsed by the Bushveld Igneous Complex. Helicitic biotite, staurolite, and cordierite all show replacement and displacement textures, the former being more common. The evidence indicates that porphyroblasts arc capable of creating lo...

the protoliths of metamorphosed argillaceous rocks from the garmichay area in the east azerbaijan province of nw iran were clay-rich sediments of reworked nature, originating most likely from an andesite to andesite-basalt source and deposited in an active continental margin tectonic setting. the protoliths of the garmichay metapelites experienced low to moderate chemical weathering. andalusite...

Abstract The aim of this work is to study the effect various talc rocks for preparation talc-based cordierite ceramics. Raw and sintered cordierite-based ceramic samples (1000-1375ºC 2 h) were characterized using XRD, XRF, TGA-DTG, laser PSDs, Archimedes method, SEM-EDAX dielectric relaxation spectrometer (DRS). Results show that impurity oxide contents, particle size mineralogical changes gree...