Papers by Keyword: Bi-Layers

Abstract: We observe a large magneto-resistance in very thin Ba₂FeMoO₆ films of ~-12% at 10K, which is not significantly changed when thin NiFe/Ba₂FeMoO₆ bi-layers are made. This suggests that the magneto-resistance in both cases is dominated by inter-grain tunnelling in the Ba₂FeMoO₆ thin film. There is an anomalous peak in the resistance at ~300K in the bi-layer film that can not be easily explained. However, we know that the temperature where this peak occurs is close to the Ba₂FeMoO₆ Curie temperature.

Abstract: When structures that consist of powders of two or more materials, such as low temperature co-fired ceramic packages or a planar solid oxide fuel cells, are sintered, the mismatch in the sintering shrinkage rates between the different materials produces stress, since the faster shrinking materials are constrained by those that shrink at a slower rate. These stresses can lead to the formation of defects such as cracks or shape distortion. Results of recent model experiments to study the constrained sintering in multi-material systems will be discussed for two model geometries. The first geometry is a simple bi-layer consisting of single layers of two different materials bonded together. Results of in situ observation of sintering bi-layers will be presented and discussed in relation to the properties of the individual layers such as their free sintering rates, uniaxial viscosities and viscous Poisson’s ratio. The second geometry studied was that of a ring of one material filled with a cylinder of a second, slower shrinking material. In this case, the results of several variations of this geometry including filling the ring either fully or partly with a rigid, nonshrinking cylinder or with rigid, non-cylindrical shapes will be presented and discussed.

Abstract: Docetaxel (form A), a stoichiometric hydrate containing three water molecules per molecule of drug substance (Taxotere^®), is thermodynamically stable under ambient conditions of pressure, temperature and relative humidity. In order to gain a better understanding of docetaxel system at the atomic scale a structural study was performed. Due to strong anisotropy of crystals (thin plates), the crystal structure of docetaxel (29 degrees of freedom) was solved and refined using high resolution XRPD data applying an ab initio direct space method. In parallel, an in-depth crystal growth study was carried out until single crystals suitable for XRSCD structural resolution were obtained: surprisingly, a new polymorph of docetaxel, called form B, was isolated.