0000000000427123
AUTHOR
I.g. Voigt-martin
TEM studies on La2−2xCa1+2xMn2O7 (x=0.5 and 0.25)
The nominal compositions and structures of the compounds La2-2xCa1+2xMn2O7 (x=0.5 and 0.25) prepared by solid-state reaction have been studied by transmission electron microscopy and high-resolution electron microscopy. Besides the observation of the major phase of a two-layer structure in the nominal composition La1.0Ca2.0Mn2O7, the embedded n = 3, n = 4 Ruddlesden-Popper phases and La rich phase in the two-layer structure were observed as defects. No layered structure was observed in the nominal composition La1.5Ca1.5Mn2O7. Instead, a major phase of orthorhombically distorted perovskite, a minor phase of an ideal cubic perovskite, and a small fraction of calcium-oxide were observed in the…
The use of simulation methods to obtain the structure and conformation of 10-cyano-9,9′-bianthryl by electron diffraction and high-resolution imaging
Abstract Experimental electron diffraction patterns and high-resolution images were used to determine the space group and unit cell dimensions of 10-cyano-9,9′-bianthryl. Subsequently the molecular conformation was calculated by semi-empirical quantum-mechanical methods. The molecule was then placed with the appropriate symmetry into the unit cell and the conformational as well as the packing energy deduced by an iterative procedure until good agreement was obtained between experiment and theory.
Studies of the Ca4Mn3O10structure obtained using high pressure and high temperature
An ideal n = 3 member of the group of Ruddlesden?Popper (RP) phases Ca4Mn3O10 was obtained by solid-state reaction under high pressure. This phase has been studied by transmission electron microscopy, convergent beam electron microscopy, high-resolution transmission electron microscopy, and parallel electron energy-loss spectroscopy. The lattice parameters are derived as a = b = 0.37 nm and c = 2.69 nm with the space group I4/mmm, which is the space group of the ideal RP phase.
CCDC 153322: Experimental Crystal Structure Determination
Related Article: R.C.Yu, A.V.Yakimansky, H.Kothe, I.G.Voigt-Martin, D.Schollmeyer, J.Jansen, H.Zandbergen, A.V.Tenkovtsev|2000|Acta Crystallogr.,Sect.A:Found Crystallogr.|56|436|doi:10.1107/S0108767300006668