76 research outputs found
Charge-transfer induced surface conductivity for a copper based inorganic-organic hybrid
Inorganic-organic hybrids are receiving increasing attention as they offer the opportunity to combine the robust properties of inorganic materials with the versatility of organic compounds. We have studied the electric properties of an inorganic-organic hybrid with the chemical formula: CuCl4(C6H5CH2CH2NH3)2. This material is a ferromagnetic insulator that can easily be processed from solution. We show that the surface conductivity of the hybrid can be increased by five orders of magnitude by covering the surface with an organic electron donor. This constitutes a novel method to dope perovskite-based materials and study their charge transport properties.
Hexagonal LuMnO3 revisited
The crystal structure of hexagonal LuMnO3 at room temperature is isomorphous with YMnO3 and deviates in important details from early work. Mn is near the centre of its oxygen coordination environment. On the threefold axes, the apical O-Lu bonds have alternating long and short bond lengths, leading to ferroelectric behaviour. The sample studied was composed of almost equal volumes of inversion twins
Hexagonal LuMnO3 revisited
The crystal structure of hexagonal LuMnO3 at room temperature is isomorphous with YMnO3 and deviates in important details from early work. Mn is near the centre of its oxygen coordination environment. On the threefold axes, the apical O-Lu bonds have alternating long and short bond lengths, leading to ferroelectric behaviour. The sample studied was composed of almost equal volumes of inversion twins
A 2:1 cocrystal of 6,13-dihydropentacene and pentacene
6,13-Dihydropentacene and pentacene cocrystallize in a ratio of 2:1, i.e. C22H16·0.5C22H14, during vapour transport of commercial pentacene in a gas flow. The crystal structure is monoclinic, space group P21/n, and contains one dihydropentacene molecule and half a pentacene molecule in the asymmetric unit.
Growth and Helicity of Noncentrosymmetric Cu<sub>2</sub>OSeO<sub>3</sub> Crystals
We have grown CuOSeO single crystals with an optimized chemical vapor
transport technique by using SeCl as a transport agent. Our optimized
growth method allows to selectively produce large high quality single crystals.
The method is shown to consistently produce CuOSeO crystals of maximum
size 8 mm x 7 mm x 4 mm with a transport duration of around three weeks. We
found this method, with SeCl as transport agent, more efficient and simple
compared to the commonly used growth techniques reported in literature with HCl
gas as transport agent. The CuOSeO crystals have very high quality and
the absolute structure are fully determined by simple single crystal x-ray
diffraction. We observed both type of crystals with left- and right-handed
chiralities. Our magnetization and ferromagnetic resonance data show the same
magnetic phase diagram as reported earlier
Anisotropy of the Mobility of Pentacene from Frustration
The bandstructure of pentacene is calculated using first-principles density
functional theory. A large anisotropy of the hole and electron effective masses
within the molecular planes is found. The band dispersion of the HOMO and the
LUMO is analyzed with the help of a tight-binding fit. The anisotropy is shown
to be intimately related to the herringbone structure.Comment: Accepted for publication in Synthetic Metal
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