[en] Highlights: • In this paper Mg-Nd-Mn nanoferrites have been synthesized for the first time by the self-ignited solution combustion method, and a maiden attempt has been made to investigate the effect of Nd³⁺ ions on the structural, magnetic & Mössbauer properties of Mg-Nd-Mn nanoferrites. • The cation distribution technique has been used to explore the detailed structural parameters. The cation distribution has been estimated by the X-ray diffraction technique and has been authenticated by using the magnetization method. • The magnetic parameters obtained in the present work are suggesting their utility for electromagnet applications. - Abstract: The present work is focused on the replacement of Fe³⁺ ions by rare-earth Nd³⁺ ions and their influence on the cations distribution, structural, magnetic and Mössbauer properties of Mg-Mn nanoferrites. Nanosized Nd-doped Mg-Mn nanoferrites, Mg_0.9Mn_0.1Nd_xFe_2−xO₄, where x = 0.1, 0.2 & 0.3, were successfully synthesized for the first time through solution combustion technique. X-ray diffraction studies confirmed the formation of single phase nature of the synthesized nanoferrites. Williamsons-Hall plots were used to obtain the particle size and strain while the lattice parameter was obtained from Nelson-Riley plots. The particle size was observed to decrease (19.2–13.5 nm) while lattice parameter was observed to increase (8.373–8.391 Å) with the incorporation of Nd³⁺ ions. Cation distribution between the tetrahedral (A-site) and octahedral (B-site) was estimated by using the X-ray diffraction method & magnetization technique. The estimated cation distribution was used to investigate the detailed structural parameters. Room temperature M−H study revealed a decrease of saturation magnetization (10.15–1.83 emu/g) and an increase in coercivity (22.86–27.19 Oe) with the increasing substitution of Nd³⁺ ions. Magnetic results obtained in the present study indicated that the synthesized nanoferrites can be a useful candidate for electromagnet applications.

[en] As a novel class of inorganic phosphor, the alkali-alkaline earth borate phosphors have gained huge attention due to their charming applications in solid-state lighting (SSL) and display devices. The current research drive shows that phosphors based on the alkali-alkaline earth borates have transformed the science and technology due to their high transparency over a broad spectral range, their flexibility in structure and durability for mechanical and high-laser applications. Recent advances in various aspects of rare-earth (RE) doped borate based phosphors and their utilizations in SSL and light emitting diodes are summarized in this review article. Moreover, the present status and upcoming scenario of RE-doped borate phosphors were reviewed in general along with the proper credential from the existing literature. It is believed that this review is a sole compilation of crucial information about the RE-doped borate phosphors in a single platform.

[en] This work investigates the structural, optical and photometric characterization of a Eu²⁺/Dy³⁺ doped calcium aluminates phosphor (CaAl₂O₄: Eu²⁺/Dy³⁺) for finger and lip print detections. Synthesis of CaAl₂O₄: Eu²⁺/Dy³⁺ (CAED) phosphors were carried out via a combustion synthesis method with urea as a fuel. Eu²⁺/Dy³⁺ doped CaAl₂O₄ phosphors have been studied with X-ray diffraction (XRD, Energy Dispersive X-Ray Spectroscopy Selected Area Diffraction (SAED) and High resolution Transmission Electron Microscope (HR-TEM). The XRD pattern shows that the synthesized Eu²⁺/Dy³⁺ doped CaAl₂O₄ phosphor have a single monoclinic structure and show that the addition of the dopant/co-dopants didn’t change the crystal structure. The formation of monoclinic phase was confirmed by the selected area diffraction pattern. The TEM micrograph displays the morphology of the synthesized Eu²⁺/Dy³⁺ doped CaAl₂O₄ phosphors as spherical particles with an average particle size of 33 nm. The optical band gap was calculated using the diffuse reflectance for the synthesized nanophosphor powders. The photoluminescence emission spectra was recorded for the synthesized powder, with an excitation wavelength of 326 nm and the major bands was recorded at 447 nm corresponding to the blue color and two minor bands were recorded at 577 nm and 616 nm. To the best of our knowledge, this work is the first to show the use of CaAl₂O₄: Eu²⁺/Dy³⁺ nanophosphor in developing latent fingerprint and lip print effectively.

[en] NaYF₄ is regarded as the best upconversion (UC) matrix owing to its low phonon energy, more chemical stability, and a superior refractive index. This review reports on the various synthesis techniques of lanthanide-doped NaYF₄ phosphors for UC application. The UC intensity depends on different properties of the matrix and those are discussed in detail. Plasmon-enhanced luminescence UC of the lanthanide-doped NaYF₄ core-shells structure is discussed based on a literature survey. The present review provides the information about how the UC intensity can be enhanced. The idea about the UC is then deliberately used for versatile applications such as luminescent materials, display devices, biomedical imaging and different security appliances. In addition, the present review demonstrates the recent trends of NaYF₄ UC materials in solar cell devices. The role of NaYF₄ phosphor to eradicate the spectral variance among the incident solar spectrum, semiconductor as well as the sub-band gap nature of the semiconductor materials is also discussed in detail. Considering the fact that the research status on NaYF₄ phosphor for photovoltaic application is now growing, the present review is therefore very important to the researchers. More importantly, this may promote more interesting research platforms to investigate the realistic use of UC nanophosphors as spectral converters for solar cells.

[en] Electrospinning has attracted a worldwide interest as a technique for the production of nanofibrous membranes with diameter ranging 2 nm to several microscales using natural and synthetic polymers. The electrospun nanofibres have advantages such as high surface area, easy surface modification, functionalization of polymeric chains, inexpensive and tunable thermo-mechanical properties. Moreover, electrospinning is one of the simplest techniques for the incorporation of nanofillers into polymeric nanofibres. Herein, we review the preparation and applications of natural and polymer-based nanofibrous membranes. We focus on applications of the electrospun membrane for energy storage, water purification and biomedical. Furthermore, we show surface morphologies of nanofibrous membranes using fast emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy, Brunauer–Emmett–Teller and micrographs.