Complex oxides with perovskite-like crystalstructures are of great interest due to their unique properties: high-temperature superconductivity, colossal magnetoresistance [ 1 , 2 ], photocatalytic activity in
Authors:Behzad Koozegar Kaleji, Rasoul Sarraf-Mamoory, and Sohrab Sanjabi
anatase crystalstructure is more favorable than rutile as it is more active with band gap energy of 3.2 eV than rutile (3.0 eV) [ 29 , 30 ].
Consequently, the reason for the increase in the photocatalytic activity of film B should be ascribed to
Authors:R. Kusiorowski, T. Zaremba, J. Piotrowski, and J. Adamek
temperatures which may lead to changes in crystalstructure and the formation of new phases without the dangerous properties. This method can be realized by the conventional thermal treatment [ 6 , 23 – 27 ] or with the use of microwave radiation [ 3 , 28
Authors:Claudia Aparicio, Libor Machala, and Zdenek Marusak
destroyed and crystalline ferrous ferrocyanide with undetermined crystalstructure was formed. On the other hand, when the PB sample was heated in air at 410 °C they obtained magnetite in addition to the above-mentioned phases.
Other study on PB
Authors:G. Perlovich, L. Hansen, and A. Bauer-Brandl
Single crystals of the N,N-dimethylformamide (DMF) solvate (1:1) of flurbiprofen (FBP) were grown for the first time and characterised
by X-ray diffraction, IR spectrophotometry, DSC and solution calorimetric methods. The structure may be characterised as a
layer-structure, where DMF double-sheets are arranged between FBP double-sheets. The FBP and DMF molecules are linked to each
other by a hydrogen bond, which is formed between the hydroxyl group of FBP and the carbonyl group of DMF. The conformation
of FBP molecules in the DMF solvate differs from analogous enantiomers in the unsolvated form. The differences are discussed
from the point of view of the influence of the nature of the solvent on selective crystallisation of the enantiomers. A peculiarity
of the solvate is its low melting point, 37.30.2C, with respect to the unsolvated phase, 113.50.2C. Based on solution
enthalpies of the solvated and unsolvated phases dissolved in DMF, the difference in crystal lattice energies, 9.8 kJ mol-1, was calculated and the difference in entropies, 33 J mol-1 K-1 estimated. A possible mechanism explaining the low melting point of the solvate is discussed.
Authors:T. Tanaka, J. Magoshi, Y. Magoshi, B. Lotz, S.-I. Inoue, M. Kobayashi, H. Tsuda, M. Becker, Zh. Han, and Sh. Nakamura
The crystal structure, thermal properties and growth rates of spherulites of the Tussah silk fibroin, produced upon drying
of the silk taken directly from the lumen which is essentially a poly(L-alanine)polypeptide, are investigated. Depending on casting conditions, spherulites with either αhelical chain conformation
or β parallel sheet structure are produced. The growth rates display a strong positive temperature coefficient, with an apparent
transition, which however cannot be related with the formation of two different crystal structures at this stage.
Authors:P. Kovacheva, N. Minkova, D. Todorovsky, and D. Radev
The effect of the mechanical treatment of UO2(CH3COO)2·2H2O in a planetary ball mill in air or as a suspension in toluene or benzene on its crystal structure and coordination mode
has been studied. No significant changes in the crystal structure are observed. IR-spectroscopy results suggest that in the
part of the mechanoactivated material the bidentate bonding of the CH3COO− is transformed in monodentate one. The newformed species is soluble in non-polar solvents.
Authors:Imre Miklós Szilágyi, Eero Santala, Mikko Heikkilä, Marianna Kemell, Timur Nikitin, Leonid Khriachtchev, Markku Räsänen, Mikko Ritala, and Markku Leskelä
Weiner , H , Lunk , HJ , Friese , R , Hartl , H . Synthesis, crystalstructure, and solution stability of Keggin-type heteropolytungstates (NH 4 ) 6 Ni 0.5 II [α-Fe III O 4 W 11 O 30 Ni II O 5 (OH 2 )]· n H 2 O