Reactive DC magnetron sputtered zirconium nitride (ZrN) thin film and its characterization

Nanomechanical properties of zirconium anodized in a mixture of electrolytes with fluoride ions

The present work introduces nanostructured Zr as a possible choice of metallic implant biomaterial in competition with titanium and its new alloys. The paper reports on the preparation of anodized zirconium in a mixture of electrolytes with fluoride ions, 1 M (NH₄)2SO₄ + 0.15 M NH₄F + distilled water, at 20 V. The obtained nanostructures were investigated by SEM, EDX, XRD and AFM techniques. The SEM - EDX longitudinal and cross sectional analysis revealed the morphology of the formed oxide layers and their thicknesses, which were found to be 7.45 ± 0.18 μm. The mean nanopores' diameter was calculated as 15.8 ± 3.3 nm. The XRD investigations enabled the evaluation of crystallite sizes and texture coefficients for zirconium and zirconium oxide containing samples. The inhibition effect against Escherichia coli and Streptococcus Aureus bacteria was evaluated and discussed as well. The AFM studies revealed that the nano-porous Zr has similar hardness parameter as the uncoated Zr, but lower surface adhesion force that could be translated into improved properties in terms of antimicrobial effects, as confirmed by its inhibition index, which makes it a very promising material for bio-medical applications.

Top-Down Reactive Approach for the Synthesis of Disordered ZrN Nanocrystalline Bulk Material from Solid Waste

Transition metal nitrides possess superior mechanical, physical, and chemical properties that make them desirable materials for a broad range of applications. A prime example is zirconium nitride (ZrN), which can be obtained through different fabrication methods that require the applications of high temperature and pressure. The present work reports an interesting procedure for synthesizing disordered face centered cubic (fcc)-ZrN nanoparticles through the reactive ball milling (RBM) technique. One attractive point of this study is utilizing inexpensive solid-waste (SW) zirconium (Zr) rods as feedstock materials to fabricate ZrN nanopowders. The as-received SW Zr rods were chemically cleaned and activated, arc-melted, and then disintegrated into powders to obtain the starting Zr metal powders. The powders were charged and sealed under nitrogen gas using a pressurized milling steel vial. After 86 ks of milling, a single fcc-ZrN phase was obtained. This phase transformed into a metastable fcc-phase upon RBM for 259 ks. The disordered ZrN powders revealed good morphological characteristics of spherical shapes and ultrafine nanosize (3.5 nm). The synthetic ZrN nanopowders were consolidated through a spark plasma sintering (SPS) technique into nearly full-density (99.3% of the theoretical density for ZrN) pellets. SPS has proven to be an integral step in leading to desirable and controlled grain growth. Moreover, the sintered materials were not transformed into any other phase(s) upon consolidation at 1673 K. The results indicated that increasing the RBM time led to a significant decrease in the grain size of the ZrN powders. As a result, the microhardness of the consolidated samples was consequently improved with increasing RBM time.

Hot-Air-Assisted Fully Air-Processed Barium Incorporated CsPbI2Br Perovskite Thin Films for Highly Efficient and Stable All-Inorganic Perovskite Solar Cells

Replacement of conventional organic cations by thermally stable inorganic cations in perovskite solar cells (PSCs) is one of the promising approaches to make thermally stable photovoltaics. However, conventional spin-coating and solvent-engineering processes in a controlled inert atmosphere hamper the upscaling. In this study, we demonstrated a dynamic hot-air (DHA) casting process to control the morphology and stability of all-inorganic PSCs which is processed under ambient conditions and free from conventional harmful antisolvents. Furthermore, CsPbI₂Br perovskite was doped with barium (Ba²⁺) alkaline earth metal cations (BaI₂:CsPbI₂Br). This DHA method facilitates the formation of uniform grain and controlled crystallization that makes stable all-inorganic PSCs which enables an intact black α-phase under ambient conditions. The DHA-processed BaI₂:CsPbI₂Br perovskite photovoltaics shows the champion power conversion efficiency (PCE) of 14.85% (reverse scan) for a small exposure area of 0.09 cm² and 13.78% for a large area of 1 × 1 cm² with excellent reproducibility. Interestingly, the hot-air-processed devices retain >92% of the initial efficiency after 300 h. This DHA method facilitates a wide processing window for upscaling the all-inorganic perovskite photovoltaics.

Tuning band structure and electronic transport properties of ZrN nanotube--a first-principles investigation

The band structure and electronic transport properties of pristine ZrN nanotube, oxygen, fluorine and niobium substituted ZrN are successfully optimized using density functional theory. The transport properties of ZrN nanotube are studied in terms of band structure, density of states, electron density and transmission spectrum of ZrN nanotube. The band structure reveals that the nanostructures show metallic nature due to orbital overlapping of zirconium and nitrogen atoms. The density of states gives the information of localization of charges in energy intervals. The major contribution in density of states arises from p and d orbitals of zirconium and nitrogen atoms. The electron density is observed more in nitrogen sites for pristine and impurity substituted ZrN nanotube. The electrons near the Fermi level contributes more to the transmission, the impact in the transmission is seen due to substitution impurity and position of the defect in the ZrN nanotube. The results of the present work focus light to tailor ZrN nanotube with enhanced electronic properties in nanoelectronics applications.