Synthesis and physical properties of nanopowder and electrical properties of bulk samples of ZnFe2-xNixO4 (x: 0, 0.05, 0.10)

Recent developments on graphene and its derivatives based electrochemical sensors for determinations of food contaminants.

The silver nanoparticle (AgNP) ink synthesized was simple, well-dispersed, did not need sintering, had excellent conductivity and can be used as a conductive ink in several areas, particularly in the fabrication of reference electrodes. The AgNP ink was fabricated by synthesizing AgNP using the polyol method and then dispersing in methanol to fabricate the conductive ink. The synthesis was explained step-by-step, the proposed mechanism was discussed and photos of the entire process were shown. The materials (AgNO3 and AgNP) were characterized by UV–Vis, SEM and XRD. The UV–Vis exhibit a strong broad peak at 417 nm due the surface plasmon resonance (SPR) absorption band of AgNP. The SEM images showed spherical nanoparticles, non-aggregates and with an average diameter of 50 - 140 nm. The XRD of AgNP presented four main characteristic peaks for silver corresponding to (111), (200), (220) and (311) planes, confirming the cubic (FCC) silver. The AgNP ink has an excellent conductivity, with an average ohmic resistance of 1.53 Ω. Finally, the AgNP ink was tested in the fabrication of reference electrodes and the analytical response was higher than the conventional Ag/AgCl reference electrode. 

Synthesis of a silver nanoparticle ink for fabrication of reference electrodes

A lead-free multiferroic double perovskite BiHoNiTiO6 (BHNT) was prepared at high temperature following mixed oxide solid state reaction mechanism. Structural evaluation by X-ray diffractogram sugg...

Electrical and Dielectric Characterization of Bismuth Holmium Nickel Titanate (BiHoNiTiO6)

Four powder samples of Nickel ferrite (NiFe2O4) with different morphology and nanoparticle size have been synthesized by various methods: electrospinning, hydrothermal, green, and sol-gel. Through the use of XRD, FT-IR, SEM, TEM, and BET techniques, the prepared powders were characterized. The produced ferrite displayed a cubic spinel phase with various nanofiber, nanotube, nanorod, and nanosphere morphological structures. The electrical conductivity values for each sample increased with increasing temperature indicating the semiconducting behavior of all samples. The conductivity values were found to be dependent on each nanoparticle's size and morphology. The variation of dielectric constant (ε′), dielectric loss (ε′′), and ac conductivity for the investigated samples at different temperatures and frequencies has been studied. Both dielectric constant (ε′) and dielectric loss (ε′′) were decreased with the increase of frequency while A.C. conductivity increased. Knop's phenomenological theory explains the frequency variation of (ε′ and ε′′). The hopping of electrons and holes is suggested to be the electrical conduction mechanism. 

Effect of Morphology and Particle Size on the Electrical Properties of Nano-Nickel Ferrite

The influence of grain size (7-16 nm) on electrical conductivity, dielectric properties and magnetic field dependent I–V characteristics along with magnetoresistance have been studied for zinc ferr...

Prabir Ghosh

Papers

Influence of Particle Size on the Electrical Properties and Magnetic Field Dependent I–V Characteristics of Nanocrystalline ZnFe2O4