Investigation of spectral properties of potassium-aluminum-borate glass with CuCl - CuBr nanocrystals

Heat treatment conditions effect on the characteristics of exciton absorption and luminescence of CuCl and CuBr nanocrystals in potassium-aluminaborate glass is studied. The size effect of the band edge absorption and luminescence energy is confirmed. The simultaneous presence of copper halide nanocrystals and free monovalent copper ions in the glass matrix is shown. Possible conditions for the formation of mixed CuCl-CuBr crystals are considered.

Partially stabilized zirconia (3Y-ZrO2) aluminum borate (Al18B4O33) needles composite materials by direct sintering

Novel 1:1 Yttria partially stabilized zirconia (PSZ) - aluminum borate (AB: Al11B4O33) ceramic composites were prepared and characterized by a simple direct sintering process of PSZ-mixtures. Sintering was performed below 1300?C to minimize the decomposition of borate. Phases were corroborated by XRD. SEM permitted to characterize the microstructure as interlocking needles of - rounded by PSZ grains. Porous microstructure configuration was achieved by the proposed processing route. Porosity was within 30% for samples thermally treated at 1200 and 1300?C. Mechanical behavior was evaluated by diametral compression. A fragile behavior was observed. Both strength and apparent Young modulus were evaluated being ?30 MPa and ?3 GPa respectively; values four times higher than the corresponding alumina-AB composite. This is more important when firing at higher temperature. The density of the obtained composites coupled with the mechanical behavior are the main characteristics of this novel composite with potential structural, insulating and filtering applications.