Effect of Some Metal Ion Dopants on Electrochemical Properties of Ni(OH)_2 Film Electrode

The Ni(OH) 2 film electrodes doped respectively with alkali-earth metal aluminum, lead, partial transition metal and some rare-earth metal(altogether 17 kinds of metals) ions were prepared by cathode electrodeposition. The electrode reaction reversibility, the difficult extent of oxygen evolution, the proton diffusion coefficient, the discharge potential of middle value and the active material utilization of the Ni(OH) 2 film electrode were compared with those of the ones doped with the metal ions by means of cyclic voltammetry, potential step and constant current charge-discharge experiments. It was found that Ca 2+ , Co 2+ , Cd 2+ , Al 3+ etc. have obviously positive effect.

Metal dopants in HfO_2-based RRAM: first principle study

Based on density-functional theory （DFT）, the effects of metal dopants in HfO2-based RRAM are studied by the Vienna ab initio simulation package （VASP）, Metal dopants are classified into two types （interstitial and substitutional） according to the formation energy when they exist in HfO2 cell. Several conductive channels are observed through the isosurface plots of the partial charge density for HfO2 doped with interstitial metals, while this phenomenon cannot be found in HfO2 doped with substitutional metals. The electron density of states （DOS） and the projected electron density of states （PDOS） are calculated and analyzed; it is found that the conduction filament in HfO2 is directly formed by the interstitial metals and further, that the substitutional metals cannot directly generate conduction filament. However, all the metal dopants contribute to the formation of the oxygen vacancy （Vo） filament. The formation energy of the Vo and the interaction between metal dopants and Vo are calculated; it is revealed that the P-type substitutional metal dopants have a strong enhanced effect on the Vo filament, the interstitial metal dopants have a minor assistant effect, while Hf-like and N-Woe substitutional metal dopants have the weakest assistant effect.

Metal-Doped Brushite Cement for Bone Regeneration

For the past several years,calcium phosphate cement was used in the biomedical applications.Outstanding biocompatibility,good bioactivity,self-setting qualities,minimum setting degree,appropriate toughness,and simple shape to accommodate any difficult geometry are among their most notable attributes.Calcium phosphate has some types and brushite is one of the most attractive mineral for bone repair application.Brushite is extensively employed in filling fractures and trauma treatments as a bone substituted material.This kind of material can potentially be used as a medicine delivery device.The replacement of metal,such as magnesium,zinc,and strontium ions,into the calcium phosphate structure is a major research topic these days.Brushite cement has low mechanical strength and quick setting rate.It is possible to produce biomaterials with higher mechanical characteristics.By adding metal that are great potential in controlling cellular density when included into biomaterials.As a result,it is a successful method to develop quite well regenerative medicine.This paper provides a detailed summary of the present achievements of metal-doped brushite cement for bone repair and healing process.The major purpose of this work is to give a simple but thorough analysis of current successes in brushite cement doped with Zn,Mg,Sr,and other ions as well as to highlight new advancements and prospects.The impact of metal replacement on cement physical and chemical properties,including microstructure,setting time,injectability,mechanical property,and ion release,is explored.The metal-doped cement has osteogenesis,angiogenesis,and antibacterial properties,as well as their prospective utility as drug carriers,also considered.