Effect of Zirconium Doping on Electrical Properties of Aluminum Oxide Dielectric Layer by Spin Coating Method with Low Temperature Preparation

In recent years, significant efforts have been devoted to the research and development of spin-coated Al2O3 thin films, due to their large band gaps, high breakdown voltage and stability at high annealing temperature. However, as the alumina precursor has a large surface energy, substrates need to be treated by plasma before spin coating. Therefore, to avoid the expensive and process-complicated plasma treatment, we incorporated zirconium nitrate into the aluminum nitrate solution to decrease the surface energy of the precursor which improve the spreadability. Then, the electrical performances and the surface morphologies of the films were measured. For comparison, the pure Al2O3 films with plasma treatments were also prepared. As a result, after low temperature annealing (200 °C), the relative dielectric constant of Zr–AlOx spin-coated thin-film MIM (Metal-Insulator-Metal) devices can reach 12 and the leakage current density is not higher than 7.78 × 10−8 A/cm2 @ 1 MV/cm when the concentration of zirconium nitrate is 0.05 mol/L. The Aluminum oxide film prepared by zirconium doping has higher stability and better electrical properties than the pure films with plasma treatments and high performance can be attained under low-temperature annealing, which shows its potential application in printing and flexible electronic devices.

Preparation of Zirconium Diboride Nanopowders Using Different Zirconium Sources via Sol-Gel Method

Zirconium diboride nanopowders were synthesized by sol–gel method using different zirconium sources of zirconium carbonate and zirconium nitrate based on different gelling processing. Both of zirconium source can be applied in the synthesis of good performance ZrB2 powders while the in-suit sol-gel using zirconium carbonate tend to form the spherical ZrB2 powders about 50nm and the traditional sol-gel using zirconium nitrate prefer to form worm ZrB2 powders about 200nm. The influences of B/Zr molar ration of zirconium carbonate and zirconium nitrate of sol-gel method on the phase constitution was investigated. And the gel mechanism was discussed to explain the different phase constitution, morphology of final products.

Synthesis and Characterization of Neodymium Zirconate Nanocrystals Doped with Aluminium Ions by a Salt-Assistant Combustion Method

Neodymium zirconate nanocrystals doped aluminium ion NdxAl2-xZr2O7 with pyrochlore structure were prepared by a salt-assistant glycine combustion method. Zirconium nitrate, aluminium nitrate and neodymium nitrate were used as chemicals, and glycine was used as burning agent. The as-prepared NdxAl2-xZr2O7 nano-crystals were characterized by XRD, FT-IR, TEM and HRTEM. The results showed the Nd ions can be partially replaced by Al ions. For crystalline Nd1.9Al0.1Zr2O7, there are four strong diffraction peaks at 2θ = 29.02°, 33.70°, 48.37° and 57.37° corresponding crystal faces are 0.308nm, 0.266nm, 0.188nm and 0.161 nm, respectively, which indicates that the interstices of corresponding crystal faces are smaller than that of Nd2Zr2O7. Furthermore, the fluorescent properties of Nd1.9Al0.1Zr2O7 nano-crystals evaluated by the fluorescence spectra indicate that the prepared nano-crystals are a kind of potential fluorescent-emitted material.

Biomorphic Mesoporous Ce1−xZrxO2 Nanostructures Fabricated from Paper Templates

A simple and versatile procedure was developed for synthesizing biomorphic mesoporous Ce1-xZrxO2. Aqueous cerium nitrate and zirconium nitrate solutions, and paper were used as the starting materials. Under the structure-directed effect offered by the active hydroxyl radicals of the cellulose in the paper templates, porous and fibrous structures of paper were replicated by the self-assembly of Ce1-xZrxO2 nanocrystallites after the paper underwent chemical infiltration and calcinations. The product, composing of interwoven network of fibers with diameter ranging from 10 to 20 <mu>m, was a replica of the original paper structure only that each fiber was assembled by Ce1-xZrxO2 nanocrystallites with grain size of 3-10 nm. The templating function of cellulose and the mechanism in the formation of nanocrystallites were proposed.