Electron and light microscopy studies on the domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I ferroic boracites
The domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I boracite single crystals were studied by means of polarized light in conjunction with electron microscopy. Single crystals of the three compositions were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 900 °C and were examined by polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For both PLM and SEM, the same as‐grown samples were used without having to resort to metallization of the crystal faces. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of these ferroelectric/ferroelastic materials previously observed between the crossed polars of an optical microscope. X‐ray diffraction analysis of the pulverized crystals was performed for this triad of halogen boracites containing zinc as a common metal.
Transmission electron and optical microscopy of the domain structure of Ni3B7O13Br ferroic boracite
The study investigated the domain structure of nickel bromine boracite single crystals, by means of polarised-light in conjunction with transmission electron microscopy. Single crystals of Ni3B7O13Br were grown by chemical transport reactions in closed quartz ampoules, in the temperature range of 1130 K and were examined by polarising optical microscopy (PLM), and transmission electron microscopy (TEM). PLM was also used in order to study the behaviour of birefringence as a function of temperature. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of this fully ferroelectric/fully ferroelastic material previously observed between the crossed polars of an optical microscope. X-ray diffraction analysis of the crystal under study was performed at room temperature. (c) 2005 Published by Elsevier B.V.
SCIENCE AND EMPIRICISM IN PILE FOUNDATION DESIGN
Scientific approaches to pile design have advanced enormously in recent decades and yet, still, the most fundamental aspect of pile design—that of estimating the axial capacity—relies heavily upon ...