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In this research, zinc oxide (ZnO) and zinc oxide/baghdadite (ZnO/Ca3ZrSi2O9) were prepared on the surface of Mg alloy using physical vapor deposition (PVD) coupled with electrophoretic deposition (EPD). For this purpose, the nanostructured ZnO was prepared with a thickness of 900 nm and crystallite sizes of 64 nm as under layer while nanostructured baghdadite with a thickness of 10 µm was deposited on the Mg alloy substrate as an over-layer. Electrochemical measurement exhibited that the ZnO/Ca3ZrSi2O9-coated specimen has a higher corrosion resistance and superior stability in simulated body fluid (SBF) solution in comparison with the ZnO-coated and bare Mg alloy samples. Antibacterial activities of the uncoated and coated specimens were evaluated against various pathogenic species (Escherichia coli, Klebsiella pneumoniae, and Shigella dysenteriae) via disc diffusion method. The obtained results showed that ZnO and ZnO/Ca3ZrSi2O9 coatings have great zones of inhibition (ZOI) against E. coli, Klebsiella, and Shigella. However, less ZOI was found around the bare Mg alloy. Therefore, ZnO/Ca3ZrSi2O9 is a promising coating for orthopedic applications of biodegradable Mg alloys considering its excellent antibacterial activities and high corrosion resistance.

This work reported a mechanochemically aided sintering process for the synthesis of BaFe 12−x Al x O 19 (x = 0.0, 0.5, 1.0, 1.5, 2.0) hexaferrite ceramic. A brief analysis was conducted on the synthesis mechanism of the pure barium ferrite, its morphology, and magnetic properties. By substitution of Al 3+ ions into BaFe 12 O 19 lattice, the size of the grains decreased and their hexagonal-plate shape tended toward a rod-like shape. These events led to a single domain nature in the grains and also an increase in their magneto-crystalline anisotropy. Single domain nature obtained a barrier against the movement of the domain walls, which led to an increase in coercivity. On the other hand, the increase of anisotropy led to the enhancement of coercivity, according to the Stoner–Wohlfarth model. The substitution of Al 3+ ions also led to the decrease of the saturation magnetization, which was because of the lower magnetic moment of Al 3+ ions (0 μB) compared to that of Fe 3+ ions (+5 μB). As a result of substituting Al 3+ ions with a value of x = 2, a maximum reflection loss of −43 dB was obtained at a frequency of 15.7 GHz.

This work is a short report on the synthesis of CeFeO 3 ceramic nanopowder from a mixture of CeO 2 and Fe 2 O 3 powders via a high energy ball milling process and subsequent heat treatment. Investigation of the magnetic, photocatalytic and absorption properties of CeFeO 3 and its potential for colossal dielectric constant (CDC) are the main objectives of the present study. The characterization tools were X-ray diffraction (XRD), transmission electron microscopy (TEM), Field emission scanning electron microscopy (FESEM), thermogravimetry (TG), differential thermal analysis (DTA), X-ray photoemission spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–vis) and Image-J software. According to the obtained results, CeFeO 3 nanopowder can be raised as a visible light-driven photocatalyst, a semiconductor material with a narrow bandgap and a weak ferromagnetic material. For the first time the CDC behavior of this ceramic was also assessed by XPS analysis which was indicative of a good colossal dielectric constant. The results were also confirmed by the measured dielectric properties.

The effects of bismuth (Bi) addition on the microstructure and corrosion behavior of the Mg-Ca-Zn-Bi alloys were evaluated using electron microscopy, electrochemical test and electrochemical impedance spectroscopy. Microstructural observations showed that Mg-1.2Ca-1Zn-xBi (x = 0.5, 1.5, 3 wt.%) are composed of Mg2Ca, Ca2Mg6Zn3 and Mg3Bi2 phases while a new phase Mg2Bi2Ca appeared after the addition of 5 and 12 wt.% Bi to the Mg-1.2Ca-1Zn alloy. Furthermore, the additions of 0.5 wt.% Bi to the Mg-1.2Ca-1Zn alloy slightly improved the corrosion behavior of the alloy, while further increase in Bi amount from 1.5 to 12 wt.% has a deleterious effect on the corrosion behavior of the ternary Mg-1.2Ca-1Zn alloy which is driven by galvanic coupling effect. Cytotoxicity tests indicate that the Mg-1.2Ca-1Zn presents higher cell viability compared to Mg-1.2Ca-1Zn-0.5Bi alloy. In addition, the cell viability of both alloys increased with increasing incubation time while diluting the extracts to 50% and 10% improved the cell viabilities. The present results suggest that the Mg-1.2Ca-1Zn-0.5Bi can be interesting candidate for the development of degradable biomaterials and it is worthwhile for further investigation in an in vivo environment.

As a member of RFeO3 system (R = rare earth ions), the magnetic and optical properties of hexagonal yttrium ferrite (YFeO3) have been rarely investigated. On the other hand, a mechanical route for synthesis of this orthoferrite ceramic has not been reported yet. The aim of the present work is to synthesize YFeO3 via high energy ball milling aided by the sintering process. Photocatalytic behavior along with magnetic and absorption properties of YFeO3 were also investigated. Besides, its potential of colossal dielectric constant was discussed in this research. X-Ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry (TG), differential thermal analysis (DTA), X-ray photoemission spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–Vis) and Image-J software were utilized for data analysis. According to the obtained results, YFeO3 can be regarded a visible light-driven photocatalyst, a semiconductor with a narrow bandgap, a weak ferromagnetic material, and a ceramic without a colossal dielectric constant.

In this study, nanostructured hardystonite (HT) and titania (TiO 2 )/hardystonite (HT) dual-layered coatings were deposited on biodegradable Mg Ca Zn alloy via physical vapor deposition (PVD) combined with electrophoretic deposition (EPD). Although a single layer nano-HT coating can decrease the corrosion rate from 1.68 to 1.02 mm/year, due to the presence of porosities and microcracks, the nano-HT layer cannot sufficiently protect the Mg substrate. In contrast, the corrosion resistance of nano-HT coating is further improved by using nano-TiO 2 underlayer since it was a smooth, very uniform and compact layer with higher contact angle (52.30°). In addition, the MTT assay showed the viability of MC3T3-E1 on the nano-HT and nano-TiO 2 /HT coatings. The results demonstrated that the two-step surface modification improved both corrosion resistance and the cytocompatibility of the Mg alloy, hence making it feasible for orthopedic applications.

In this study, microstructural evolution, mechanical properties and corrosion behavior of plasma sprayed NiCrAlY/nano-yttria stabilized zirconia (nano-YSZ) dual-layered coating on Mg–1.2Ca–3Zn alloy were investigated. NiCrAlY underlayer is composed of large amount of porosities and micro-cracks with thickness around 80–90 μm. However, nano-YSZ overlayer shows bimodal microstructure consisting of columnar grains and some partially molten parts of the nanostructured powders with thickness around 270–300 μm. The microhardness of dual-layered NiCrAlY/nano-YSZ coating is significantly higher than that of single-layered NiCrAlY. Despite that, the bonding strength of dual-layered coating is slightly higher than single-layered plasma sprayed coating. Results also showed that both single-layer NiCrAlY and dual-layer NiCrAlY/nano-YSZ coatings decreased the corrosion current density of Mg alloy from 217.1 μA/cm 2 to 114.5 and 82.4 µA/cm 2 , respectively.

A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4-aryl/alkyl-4 H -chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 3,5-dimethoxy phenol under reflux condition has been developed in aqueous EtOH media using Na 2 O-Al 2 O 3 -P 2 O 5 glass–ceramic system.

A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4-aryl/alkyl-4 H -chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 3,5-dimethoxy phenol under reflux condition has been developed in aqueous EtOH media using Na 2 O-Al 2 O 3 -P 2 O 5 glass–ceramic system.

The present study addressed the synthesis of a bi-layered nanostructured fluorine-doped hydroxyapatite (nFHA)/polycaprolactone (PCL) coating on Mg-2Zn-3Ce alloy via a combination of electrodeposition (ED) and dip-coating methods. The nFHA/PCL composite coating is composed of a thick (70-80 μm) and porous layer of PCL that uniformly covered the thin nFHA film (8-10 μm) with nanoneedle-like microstructure and crystallite size of around 70-90 nm. Electrochemical measurements showed that the nFHA/PCL composite coating presented a high corrosion resistance (R(p)=2.9×10(3) kΩ cm(2)) and provided sufficient protection for a Mg substrate against galvanic corrosion. The mechanical integrity of the nFHA/PCL composite coatings immersed in SBF for 10 days showed higher compressive strength (34% higher) compared with the uncoated samples, indicating that composite coatings can delay the loss of compressive strength of the Mg alloy. The nFHA/PCL coating indicted better bonding strength (6.9 MPa) compared to PCL coating (2.2 MPa). Immersion tests showed that nFHA/PCL composite-coated alloy experienced much milder corrosion attack and more nucleation sites for apatite compared with the PCL coated and uncoated samples. The bi-layered nFHA/PCL coating can be a good alternative method for the control of corrosion degradation of biodegradable Mg alloy for implant applications.