Ionic Transportation and Dielectric Properties of YF₃:Eu Nanocrystals.

The ionic transportation and dielectric properties of YF₃:Eu nanocrystals are investigated by AC impedance spectroscopy. The ion diffusion coefficient and conductivity increase along with the doping concentration and reach their highest values at 4% of Eu. The difference of ionic radius between Eu and Y leads to the structural disorder and lattice strain, which deduces the increase of the ion diffusion coefficient and conductivity before 4% Eu doping; then the interaction of the neighboring doping ions is dominated, which results in the difficulty of ion migration and decreases of the ion diffusion coefficient and conductivity.

Enhanced Magnetic Properties of BiFeO₃ Thin Films by Doping: Analysis of Structure and Morphology.

The improvement of ferromagnetic properties is critical for the practical application of multiferroic materials, to be exact, BiFeO₃ (BFO). Herein, we have investigated the evolution in the structure and morphology of Ho or/and Mn-doped thin films and the related diversification in ferromagnetic behavior. BFO, BiHoFeO₃ (BHFO), BiFeMnO₃ (BFMO) and BiHoFeMnO₃ (BHFMO) thin films are synthesized via the conventional sol-gel method.

Effect of Tb-doped Concentration Variation on the Electrical and Dielectric Properties of CaF₂ Nanoparticles.

Calcium fluoride (CaF₂) nanoparticles with various terbium (Tb) doping concentrations were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and alternating current (AC) impedance measurement. The original shape and structure of CaF₂ nanoparticles were retained after doping. In all the samples, the dominant charge carriers were electrons, and the F ion transference number increased with increasing Tb concentration.

Correlation between the structural change and the electrical transport properties of indium nitride under high pressure.

We report on the intriguing structural and electrical transport properties of compressed InN. Pronounced anomalies of the resistivity, Hall coefficient, electron concentration, and mobility are observed at ∼11.5 GPa, accompanied by a wurtzite-rocksalt structural transition confirmed using high-pressure XRD measurements and first-principles calculations.

In situ Hall effect measurement on diamond anvil cell under high pressure.

A method for in situ Hall effect measurement under high pressure was developed on a diamond anvil cell. The electrode was accurately integrated on one diamond anvil with regular shape. A uniform and strong magnetic field was introduced into the sample zone.

Note: The effect of sample insulation on experiment precision of resistivity measurement in a diamond anvil cell.

By use of electrical field analysis method, the accuracy of electrical resistivity measurement with the van der Pauw method in a diamond anvil cell (DAC) was investigated for the situation that sample and gasket were electrically shorted. It is revealed that metal gasket could not be used in electrical measurement in DAC if the inside wall of the sample chamber was not insulated. When the shorted area was less than 20% of the inside wall of the sample chamber, the relative error was smaller than 10%.

In situ impedance measurements in diamond anvil cell under high pressure.

Two-electrode configuration was developed for in situ electrical impedance detecting on diamond anvil cell under high pressure. The metal gasket was used as one electrode and the risk coming from electrical short between sample and interside wall of the gasket was eliminated. The configuration was evaluated and proved to be effective by measuring the electric impedance of nanocrystalline ZnS under high pressure.