Glass & Glass-Ceramics

Various lead strontium titanate borosilicate glass samples were prepared with addition of 1 mol % of chromium trioxide and graphene nanoplatelets by convention melt quench method. Their structural and optical behaviors were studied by infrared spectroscopy, ultraviolet-visible spectroscopy, and scanning electron microscopy. The infrared spectroscopic studies were carried in the wavenumber range of 400-4000 cm À1 . The energy band gap of bulk transparent glass samples were found by Tauc plots of ultraviolet-visible spectra. Surface morphological studied was done by scanning electron microscopy. The density of these prepared lead strontium titanate borosilicate glass samples were calculated by ''Archimedes principle'' of liquid displacement method.

The possibility of implementing a reaction of self-propagated high-temperature synthesis of ferrites controlled through selective laser treatment is demonstrated. The conditions of synthesis of barium hexaferrite with a chromium additive and the effect of additional annealing on the results of synthesis are investigated. The three-dimensional ceramic products obtained have sufficiently good consumer properties.

glass assemblage from the Ciudad de Vascos (Navalmoralejo, Toledo) (10th - 11th century CE) that is now housed in the Museum of Santa Cruz in Toledo (Spain). Glass was evidently scarce at the Ciudad de Vascos. Accordingly, only a limited number of fragments have been recovered during the four decades of archaeological excavations at the site and these include diverse tableware objects (glasses, cups and flasks), ornament elements (ring glass gems and beads), for personal care and perfumery (suction pads or distillers, “toilet bottles” and caps). Remarkable is the presence of decorative flat glasses probably used for architectonical decoration. The colours of the glasses range from colourless, green, yellow, blue and white to deep purple. The deep purple glass fragments from Vascos predate previous Andalusian finds and thus necessitate a reconsideration of the relative chronology of this glass type in al-Andalus.

En este artículo se presenta el estudio tipológico del conjunto de vidrios aparecidos en Ciudad de Vascos (Navalmoralejo, Toledo) (ss. X-XI) depositados en el Museo de Santa Cruz en Toledo (España). En Vascos el vidrio es un material escaso, solo un número limitado de fragmentos han sido recuperados tras cuatro décadas de excavaciones arqueológicas en el yacimiento. A pesar de ello se ha documentado un variado utillaje similar al de otros ajuares andalusíes que incluye vajilla de mesa (vasos, copas, botellas y redomas), elementos de adorno (piedras de anillo y cuentas), perfumería y cuidado personal (sublimadores o ventosas, ungüentarios, ampollas y tapones). En el conjunto es destacable la presencia de vidrios planos decorativos, posiblemente utilizados como decoración arquitectónica. El color de los vidrios varía entre los incoloros, verdes, amarillentos, azules y blancos, pero también están presentes los púrpura-morados. La aparición de fragmentos de vidrio púrpura-morado antecede a otros ejemplos conocidos y plantean la necesidad de reconsiderar la cronología de este tipo de vidrios en al-Andalus.

A novel low temperature co-fired ceramic (LTCC) composition consisting of 40 wt% Al 2 O 3 -60 wt% BBSZ (35Bi 2 O 3 :32ZnO:27B 2 O 3 :6SiO 2 ) fireable at 850 1C has been developed. The XRD study of the sintered composite shows the presence of Bi 24 Si 2 O 40 and ZnAl 2 O 4 secondary phases. The bulk samples sintered at 900 1C has dielectric constant (ε r ) of 11.3 and loss tangent (tan δ) of 0.001 at 1 MHz. Tapes of the composite have been casted on Mylar s film and the green tape has a surface roughness of 299 nm and tensile strength of 0.1 MPa. Upon sintering the tapes showed an ε r of 10.9, tan δ of 0.009 and temperature coefficient of dielectric constant (τ ε ) of 487 ppm/1C at 5 GHz, which are suitable for practical hybrid device applications.

The research focused on a collection of 37 Late Antique glass fragments, found at the archaeological site of
San Giusto (southern Italy). The analyses performed by SEMEDS, EMPA and LA-ICP-MS showed that all samples are constituted by natron-based soda-lime silica glass and allowed clarifying the distinction between Egyptian HIMT1 and HIMT2 productions. The comparison with the composition of the available glass reference groups was verified through three ternary diagrams (provided here for the first time). The results grouped San Giusto samples into HIMT1 (7 samples), HIMT2 (8 samples) and Levantine (13, plus maybe other 3 samples) productions. A convincing provenance assignment was not feasible for six samples only. The isotopic analyses (87Sr/86Sr and 143Nd/144Nd), performed on a selected set of ten samples, provided further information both in terms of glass technology and provenance, as well as in terms of reference groups characterisation. Particularly, the results demonstrated that nine out of a total of ten samples were made using a limestone-bearing sand enriched with variable amount of marine shells and provided further evidence for the distinction of the HIMT1 and HIMT2 groups; the latter overlapping the Levantine field in the 87Sr/86Sr versus εNd binary diagram. From a technological point of view, the importance of separating the likely ‘fresh’ materials from those intentionally recycled or coloured was put into clear evidence, especially in relation to provenance assignments. Lastly, an interesting technological feature has been observed in sample no. 9, where the composition of the main body of the vessel turned out to be different from that of the handle. This result provided clear evidence of the fact that different glass batches could have been used for the different parts of a single vessel body.

Faragola and Canusium potters used Ca-rich clays—widely available nearby—for the production of building materials. The clayey materials were used as received, before being fired in the local kilns at temperatures between 600 and ~1000 ° C. No technological distinctions were made in relation to the type of object to be produced (tile, brick, etc). The investigated productions are compositionally distinguishable from both coarse wares for cooking and fine table ware produced in the same archaeological sites. A fine clayey material, very similar to that used for table ware, was supplied for the production of these building materials, which are chemically, mineralogically and petrographically very similar among themselves. Hence, the Faragola and Canusium bricks and tiles cannot be easily discriminated but the presence/absence of volcanites and volcanic glass represents an effective discriminating factor, able to indicate areas of different supplies within two main deposits: the Pleistocene marine and alluvial terraced deposits, typical of northern Apulia.