Pyroelectricity and field-induced spin-flop in (4-(Aminomethyl)pyridinium) 2 MnCl 4 · 2H 2 O

Large single crystals of (4-(Aminomethyl)pyridinium) 2 MnCl 4 · 2H 2 O ( 1 ) were grown by slow evaporation of solution. The crystal structure was solved to be Pī, which belongs to the central symmetric space group. But small pyroelectric current was detected, as well as a ferroelectric hysteresis loop. The pyroelectric and the ferroelectric properties were attributed to the strain caused by defects. Temperature-dependent magnetic curves and the M – H curve show that 1 is antiferromagnetic ordering below 2.5 K. A field-induced spin-flop is observed in the antiferromagnetic ordering state.

The Hydrothermal Synthesis of BaTiO3 Nanotubes Arrays with Good Electrical Property

Barium titanate nanotubes arrays were synthetized by in-suit hydrothermal method using TiO2nanotubes as both template and reactant in titanium substrate. Highly ordered nanotubes arrays and the spacing between nanotubes are apparent. XRD indicates that the samples have excellent crystallization and perovskite structure. Typical ferroelectric hysteresis loop of as-formed barium titanate nanotubes arrays with remanent polarization and coercive field are 6.72 and 48.7kV/cm.

Sintering and Electrical Properties of Tungsten Doped Pb(Zr0.95Ti0.05)O3 Ferroelectric Ceramics

The effect of WO3 additions on the sintering ability and electrical properties of Pb(Zr0.95Ti0.05)O3 ferroelectric ceramics (PZT 95/5) was investigated. Pure and W-doped PZT 95/5 ceramics were prepared by the usual ceramic technique from raw oxides. The bulk density, microstructure, electrical properties of ceramics as a function of WO3 content were characterized. The results showed that the WO3 addition was benefit for the sintering densification of PZT, and the ceramics with 2.0 mol% WO3 addition exhibited the maximum value for the density (7.8 g/cm3) at a sintering temperature of 1250 °C. Moreover, piezoelectric constant (d33), relative dielectric constant (εr), dielectric loss (tanδ) and ferroelectric hysteresis loop of PZT 95/5 ceramics at the sintering temperature of 1250 °C all altered regularly with the change of WO3 doping level, whose optimum values were all obtained by doping 2.0 mol% WO3. The best values obtained for these parameters were: d33 = 65 pC/N, εr =314, tanδ = 0.028, Pr = 24.80 µC/cm2 and Ec = 1890 V/mm, respectively. These results show that tungsten doped Pb(Zr0.95Ti0.05)O3 ferroelectric ceramics can be hopefully used for the pulsed power devices.