Glassy rods of the multicomponent ferromagnetic $ \mathrm{Fe_{65.5}Cr_4Mo_4Ga_4P_{12}C_5B_{5.5}} $ alloy were prepared by copper-mold casting technique under a protective argon atmosphere with diameters of 1.5 mm and 1.8 mm. As-cast samples were examined by non-isothermal analysis (DSC and DTA) and X-ray diffraction (XRD). The relatively high values for reduced glass transition temperature (Trg = 0.57) and supercooled liquid region width (ΔTx ≈ 60 K) indicate good glass forming ability (GFA) and high thermal stability of the undercooled liquid relative to the crystallization process. The numerous intermetallic compounds during the devitrification process were evolved. Set of three GFA parameters are obtained: α = Tx / Tl = 0.61; γ = Tx / (Tg + Tl) = 0.39; δ = Tx / (Tl – Tg) = 1.41. The Kissinger method was applied to evaluate the apparent activation energy and the frequency factor. The rate constant of the crystallization process is estimated by Arrhenius law. The following values are calculated: Ea = 418.03 kJ/mol; Z = 1.78•1027 $ min^{-1} $; kx = 1.56 $ min^{-1} $ (for 1.5 mm), and Ea = 375.48 kJ/mol; Z = 1.88•1024 $ min^{-1} $; kx = 1.44 $ min^{-1} $ (for 1.8 mm).
Cadmium ferrite nanoparticles ($ \mathrm{CdFe_2O_4} $ NPs) have been synthesized by impregnation method followed by heat treatment. Investigation the structural and morphogical properties of CdFe2O4 NPs was done using XRD, FTIR and TEM techniques. On the other hand, $ \mathrm{CdFe_2O_4} $ NPs' magnetic characteristics were investigated. The success of the preparation technique utilized to produce pure nanocrystalline pure $ \mathrm{CdFe_2O_4} $ with a size of 26 nm was validated by XRD findings. According to FTIR based functional groups, the resulting cadmium ferrite has random spinel structure. The morphological characteristics of the synthesized ferrite, as determined by TEM technique, highlight the production of spherical-like particles at the nanoscale. Additionally, the prepared ferrite displays low magnetization and coercivety with paramagnetic behavior. The current work provides new opportunities for the simple, cost-effective, and efficient synthesis of nanomaterials for usage in useful application such as gas sensing and photo catalysis.
Flexible polymers modified with copper sulfides have emerged as a novel class of materials, presenting composite structures with remarkable properties suitable for applications in flexible electronics. This study focuses on the deposition of copper sulfide ($ \mathrm{Cu_x}S $) layers onto the surfaces of polyamide and polypropylene through the chemical bath deposition method, employing either 2 or 3 deposition cycles. The objective is to explore the impact of deposition cycles and discern the optimal conditions for the deposition process. Comprehensive analysis of the $ \mathrm{Cu_x}S $ thin films entails techniques such as scanning electron microscopy (SEM), Raman spectroscopy, UV-VIS spectroscopy, and X-ray diffraction to shed light on their structural and optical characteristics.
In this work, erbium oxide (Er₂O₃), a rare-earth oxide, was employed as a dopant in barium titanate (BaTiO₃) ceramics. The BaTiO₃-based materials were prepared using a conventional solid-state reaction technique. Dopant levels ranging from 0.01 to 1.0 wt.% were incorporated into the ceramic matrix. The prepared samples were sintered at 1380°C for a duration of four hours. The structural, morphological, and optical characteristics of the resulting ceramics were examined using multiple methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and photoluminescence (PL) analysis. For samples with a low Er₂O₃ concentration (0.01 wt.%), grain sizes were found to range between 10 μm and 30 μm. In contrast, increasing the dopant content to 1.0 wt.% inhibited abnormal grain growth, leading to a more refined microstructure with grain sizes in the range of 2 μm to 10 μm. Dielectric properties, including permittivity and loss, were measured as functions of both frequency and temperature in order to establish a relationship between microstructural evolution and dielectric behavior. The amphoteric nature of rare-earth ions was found to enhance dielectric permittivity while reducing dielectric losses compared to undoped BaTiO₃. Furthermore, the effect of dopant concentration on the temperature dependence of the dielectric constant was also evaluated.
The present work investigates the effects of sintering temperatures and different sintering atmospheres on M2 high-speed steel. It is well known from the pseudo-binary phase diagram that, with an increase in temperature from 1250 ºC to 1350ºC, the sintering process changes from solid-state sintering to super-solidus liquid-phase sintering, resulting in increased densification with increasing sintering temperature owing to enhanced sintering kinetics and liquid formation. The carbide particle size also increases with increasing sintering temperature, resulting in coarser carbide and the formation of a carbide network at higher temperatures. It has been observed that densification increases in H2 atmosphere to ~99% compared to N2 (81%) and Ar (93%). Furthermore, carbide forms more finely in an N2 atmosphere, but it has a higher pore density. In the H2 atmosphere, coarse carbides are uniformly distributed in the alloy; moreover, a coarse carbide network is detected in the Ar atmosphere. Furthermore, increasing the sintering temperature from 1250ºC to 1350ºC results in a rise in bulk hardness from 119 HV0.2 to 239 HV0.2. However, Bulk hardness is also improved in the H2 atmosphere to 453 HV0.2 sintered at 1300ºC.
