Multifunctional molecular ferroelectrics are exciting materials synthesized using molecular chemistry concepts, which may combine a spontaneous electrical polarization, switched upon applying an electric field, with another physical property. A high-temperature ferroelectric material is presented that is based on a chiral Zn(2+) /Dy(3+) complex exhibiting Dy(3+) luminescence, optical activity, and magnetism. We investigate the correlations between the electric polarization and the crystal structure as well as between the low-temperature magnetic slow relaxation and the optical properties.

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Large areas of electrically active regions of in-homogeneities have been revealed by the electroless photo-etching (PEC) method in GaN layers grown by the hydride vapor phase epitaxy (HVPE) technique.Variations in the local etch rate have been correlated with the variations in the free-carrier concentrations as determined by microRaman spectroscopy. The etch rate decreased linearly with the log of the carrier concentration. The latter could change by more than two orders of magnitude on the same sample. r

In this communication we report on electrical properties of nonintentionally doped (nid) type II InAs/GaSb superlattice grown by molecular beam epitaxy. We present a simple technological process which, thanks to the suppression of substrate, allows direct Hall measurement on superlattice structures grown on conductive GaSb substrate. Two samples were used to characterize the transport: one grown on a semi-insulating GaAs substrate and another grown on n-GaSb substrate where a etch stop layer was inserted to remove the conductive substrate. Mobilities and carrier concentrations have been measured as a function of temperature (77–300 K), and compared with capacitance-voltage characteristic at 80 K of a photodiode comprising a similar nid superlattice.