Effects of NiO nanoparticles on the magnetic properties and diffuse phase transition of BZT/NiO composites

A new composite system, Ba(Zr0.07Ti0.93)O3 (BZT93) ceramic/NiO nanoparticles, was fabricated to investigate the effect of NiO nanoparticles on the properties of these composites. M-H hysteresis loops showed an improvement in the magnetic behavior for higher NiO content samples plus modified ferroelectric properties. However, the 1 vol.% samples showed the optimum ferroelectric and ferromagnetic properties. Examination of the dielectric spectra showed that the NiO additive promoted a diffuse phase transition, and the two phase transition temperatures, as observed for BZT93, merged into a single phase transition temperature for the composite samples

Perovskite phase formation and ferroelectric properties of the lead nickel niobate–lead zinc niobate–lead zirconate titanate ternary system

The ternary system of lead nickel niobate Pb(Ni1/3Nb2/3)O3 (PNN), lead zinc niobate Pb(Zn1/3Nb2/3)O3 (PZN), and lead zirconate titanate Pb(Zr1/2Ti1/2)O3 (PZT) was investigated to determine the influence of different solid state processing conditions on dielectric and ferroelectric properties. The ceramic materials were characterized using x-ray diffraction, dielectric measurements, and hysteresis measurements. To stabilize the perovskite phase, the columbite route was utilized with a double crucible technique and excess PbO. The phase-pure perovskite phase of PNN–PZN–PZT ceramics was obtained over a wide compositional range. It was observed that for the ternary system 0.5PNN–(0.5 - x)PZN–xPZT, the change in the transition temperature (Tm) is approximately linear with respect to the PZT content in the range x [H11505] 0 to 0.5. With an increase in x, Tm shifts up to high temperatures. Examination of the remanent polarization (Pr) revealed a significant increase with increasing x. In addition, the relative permittivity ([H9280]r) increased as a function of x. The highest permittivities ([H9280]r[H11505] 22,000) and the highest remanent polarization (Pr [H11505] 25 μC/cm2) were recorded for the binary composition 0.5Pb(Ni1/3Nb2/3)O3–0.5Pb(Zr1/2Ti1/2)O3

Fabrication of transparent lead-free KNN glass ceramics by incorporation method

The incorporation method was employed to produce potassium sodium niobate [KNN] (K0.5Na0.5NbO3) glass ceramics from the KNN-SiO2 system. This incorporation method combines a simple mixed-oxide technique for producing KNN powder and a conventional melt-quenching technique to form the resulting glass. KNN was calcined at 800°C and subsequently mixed with SiO2 in the KNN:SiO2 ratio of 75:25 (mol%). The successfully produced optically transparent glass was then subjected to a heat treatment schedule at temperatures ranging from 525°C -575°C for crystallization. All glass ceramics of more than 40% transmittance crystallized into KNN nanocrystals that were rectangular in shape and dispersed well throughout the glass matrix. The crystal size and crystallinity were found to increase with increasing heat treatment temperature, which in turn plays an important role in controlling the properties of the glass ceramics, including physical, optical, and dielectric properties. The transparency of the glass samples decreased with increasing crystal size. The maximum room temperature dielectric constant (εr) was as high as 474 at 10 kHz with an acceptable low loss (tanδ) around 0.02 at 10 kHz

Effects of NiO nanoparticles on the magnetic properties and diffuse phase transition of BZT/NiO composites

A new composite system, Ba(Zr[subscript 0.07]Ti[subscript 0.93])O₃ (BZT93) ceramic/NiO nanoparticles, was fabricated to investigate the effect of NiO nanoparticles on the properties of these composites. M-H hysteresis loops showed an improvement in the magnetic behavior for higher NiO content samples plus modified ferroelectric properties. However, the 1 vol. % samples showed the optimum ferroelectric and ferromagnetic properties. Examination of the dielectric spectra showed that the NiO additive promoted a diffuse phase transition, and the two phase transition temperatures, as observed for BZT93, merged into a single phase transition temperature for the composite samples.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Springer. The published article can be found at: http://www.nanoscalereslett.com/.Keywords: microstructure, ceramics, composites, electrical properties, magnetic propertie

Ion implantation damage in gallium arsenide crystals.

Crystal damage produced by ion implantation in (110) cut gallium arsenide single crystals has been investigated using X-ray diffraction, reflection high energy electron diffraction (RHEED) and electron microscopy. Various ions were employed, Post bombardment annealing was carried out to remove damage from the crystals. Damage-depth profiles of tellurium and cadmium, and room temperature implanted specimens were measured. Annealing of these specimens without protection was carried out to study damage removal. The results proved to be very complicated, including the decomposition of the gallium arsenide, the formation of beta gallium oxide and gallium telluride, and the occurrence of preferred orientation and twinning in gallium arsenide. Comparisons were made with the annealing behaviour of ball-milled gallium arsenide using X-ray diffraction line broadening. The effects of various types of mechanical damage associated with specimen polishing of the gallium arsenide single crystals were also examined. Damage of single crystal gallium arsenide due to tellurium implantation at high temperature was studied using RHEED. The changes in the effects of annealing behaviour of implanted specimens with protective layers of silicon nitride, aluminium and native oxides were also studied. The observations obtained from RHEED were found to be in agreement with those from Rutherford Back Scattering (RBS) experiments. The formation of the dislocation loops of tellurium and tin implanted specimens were studied using transmission electron microscopy (TEM). Some correlations of defects with the electrical properties of the implanted layers were described. Some work was also carried out using mainly X-ray diffraction methods to study damage due to nitrogen implantation into sputtered tantalum thin films (500 A). The effects of post-bombardment annealing were investigated. After implantation, tantalum nitride (TaN) was formed. This recrystallised with increasing annealing temperatures. The formation of TaN was associated with changes in resistivity of the tantalum film

Ion implantation damage in gallium arsenide crystals.

Crystal damage produced by ion implantation in (110) cut gallium arsenide single crystals has been investigated using X-ray diffraction, reflection high energy electron diffraction (RHEED) and electron microscopy. Various ions were employed, Post bombardment annealing was carried out to remove damage from the crystals. Damage-depth profiles of tellurium and cadmium, and room temperature implanted specimens were measured. Annealing of these specimens without protection was carried out to study damage removal. The results proved to be very complicated, including the decomposition of the gallium arsenide, the formation of beta gallium oxide and gallium telluride, and the occurrence of preferred orientation and twinning in gallium arsenide. Comparisons were made with the annealing behaviour of ball-milled gallium arsenide using X-ray diffraction line broadening. The effects of various types of mechanical damage associated with specimen polishing of the gallium arsenide single crystals were also examined. Damage of single crystal gallium arsenide due to tellurium implantation at high temperature was studied using RHEED. The changes in the effects of annealing behaviour of implanted specimens with protective layers of silicon nitride, aluminium and native oxides were also studied. The observations obtained from RHEED were found to be in agreement with those from Rutherford Back Scattering (RBS) experiments. The formation of the dislocation loops of tellurium and tin implanted specimens were studied using transmission electron microscopy (TEM). Some correlations of defects with the electrical properties of the implanted layers were described. Some work was also carried out using mainly X-ray diffraction methods to study damage due to nitrogen implantation into sputtered tantalum thin films (500 A). The effects of post-bombardment annealing were investigated. After implantation, tantalum nitride (TaN) was formed. This recrystallised with increasing annealing temperatures. The formation of TaN was associated with changes in resistivity of the tantalum film

EFFECT OF PRE-HEATING TEMPERATURE ON THE CHARACTERISTICS OF PZT THIN FILMS GROWN BY USING A TRIOL SOL–GEL ROUTE

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt(111)/Ti/SiO2/Si(100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.Sol–gel, PZT thin films, spins coating