Nanometric scale investigation of local strain in GaInAs islands by high resolution and analytical TEM.

The continuous displacement field within elastically relaxed GaInAs islands was calculated from digitized HREM images of [110] cross sections of In0.35Ga0.65As layers grown on GaAs by molecular beam epitaxy.

Cubic mesophase in an unsymmetrical alkyl ammonium salt. Synthesis and structural model.

N,N,N-butylethylpentylpropylammonium iodide 4 and related molecules have been selectively synthesised from commercially available aldehydes, amines and alkyl iodides using a reductive alkylation procedure. The crystalline texture of 4 obtained on cooling is optically isotropic between crossed polarisers, indicating a cubic structure. Differential scanning calorimetry (DSC, +10 K min-1) reveals a glass phase transition at -59 degrees C and a melting point at 192 degrees C.