Materials Letters: X最新文献

CdSe and CdSe:Te thin films were grown on Si p-type substrates by RF magnetron sputtering method. The doping percentage of Tellurium (Te) in CdSe was 7% for the CdSe:Te thin film. The results show that after the doping of Te in the CdSe thin film, the conductivity changes from n-type to p-type and the mobility of the CdSe thin film increased. The conductivity of Te doped CdSe was found to be in order of 10⁻⁶ Ω⁻¹ cm⁻¹, while without doping it was 10⁻⁵ Ω⁻¹ cm⁻¹. X-ray diffraction (XRD) confirmed the presence of CdSe, Te and Si.

In the present work, ²⁴¹Am incorporated in SrBPO₅ (SBP) host matrix was investigated by various spectroscopic techniques to understand the trap level spectroscopic properties of the system. Photoluminescence (PL) depicted stabilization of Am in +3 oxidation state with low local symmetry. Thermoluminescence (TL) on the other hand suggested that creation of self irradiated defects in SBP:²⁴¹Am leads to a glow curve around 463 K. Electron spin resonance (ESR) further confirmed the creation of borate radical in axial symmetry on doping ‘Am’ in SBP with hyperfine splitting. We could further propose the mechanism of TL glow curve on doping Am in the SBP lattice.

Core@shell nanomaterials are a class of materials containing a core and a shell, both at the nanometer scale, as they have become a consequential research interest owing to their optical, electrical, and magnetic properties. Moreover, various core@shell nanomaterials have also emerged in many other fields, such as catalysis, pharmaceuticals, and biomedical due to their less toxicity, surface area, good biocompatibility, adequate penetration power for biological tissue, and selectivity for target molecules. Hence, this review covers the optical properties of core@shell nanomaterials and biosensors based on various core@shell nanomaterials, for example, inorganic@inorganic (Au@Ag), organic@inorganic (polyurethane@Au), inorganic@organic (CeO₂@polyaniline), and organic@organic (poly(vinylidene difluoride)@dopamine) for biomedical applications; along with this, it also discusses the advantage and disadvantage of core@shell nanomaterials.

FeCrAl alloys are among the most promising candidates for accident-tolerant fuel cladding material in light water nuclear reactors. Despite their high-temperature oxidation resistance in corrosive environments coupled with their hydrothermal corrosion resistance, a key challenge remains in optimizing the composition of the alloy that can be achieved through statistical analysis. However, the current literature on FeCrAl alloy design lack studies for designing alloys based on oxidation resistance. This study addresses that gap by developing a predictive model for the oxidation of FeCrAl alloys based on an experimental dataset, which lays the groundwork for model-based optimization for alloy composition.

In the present work, the effect of deposition time (10 min, 20 min, and 30 min) on the structural, morphological, and electrical properties of Al/Ta thin films has been investigated. The XRD and microscopy results revealed that the thin films exhibit a bcc structure, with a strong (1 1 0) preferred orientation and followed a columnar growth with grain sizes lower than 100 nm. Thin film with 20-min deposition time exhibits less average roughness and better morphology than 10-min and 30-min. Further, the average resistance was smallest for thin films with 20-min of deposition time along with the optical reflectance between 50 and 85% in wavelength region of 400–1000 nm. The Al/Ta thin film can be employed as an excellent back-contact material for thinfilm solar cells due to its improved crystallinity, reflectance, and lower resistivity.

In the present paper, we reported the sensing behavior and mechanism of a titanium dioxide-based thick film sensor for the detection of propanol at room temperature. Undoped titanium dioxide (UTO) and 2 wt% cadmium sulfide doped titanium dioxide (CdTO) thick film samples are fabricated on an alumina substrate. The response of the fabricated samples is measured with varying concentrations of propanol (0–5000 ppm) in a testing chamber at room temperature. The measurement showed that the 2 wt% CdS doped sample showed a maximum response (63 %) for propanol. The transient response is also measured and the response time is 65 s and recovery 195 s.

Various rod-shape SnO₂ nanocrystals of different sizes and shapes were synthesized to study the desirable morphology for photocatalytic applications. An optimal apparent photocatalytic rate constant of 0.0809/min⁻¹ was achieved for smaller SnO₂ nanorods with diameter of ∼2.9 nm and with length of ∼9.3 nm, which is attributed to suitable nanostructures and high crystallinity. Photocatalytic activities as a function of growth and evolution of SnO₂ nanorods are revealed.

Herein, characteristics of the nanostructured silica powders (NsSP) synthesized from Philippine rice hull ash-based sodium silicate solution by precipitation (pH 2, pH 6) and calcination (600 °C, 900 °C) were presented. Characterizations confirmed that the synthesized NsSP contains high amount of SiO₂. NsSP obtained at pH 2 revealed higher mass losses by ∼ 12 % until 900 °C and higher intensities of –OH and Si–OH bonds than obtained at pH 6. Calcination of NsSP at 900 °C removes the Si–OH bond leading to a relative growth in the SiO₂ primary particles but SiO₂ structure remained amorphous. Morphology of NsSP obtained at pH 2 were cloud-like while NsSP obtained at pH 6 were bead-like and more distinct.

Composite polyurethane (PU) foams were effectively synthesized by the mass polymerization method with concentrations of natural basalt powder from 0 to 100 wt%. By increasing basalt's content, the foams had more considerable growth, suggesting a catalyst effect of its inherent metallic compounds during the reaction. Adding basalt powder decreased the traction and compression resistances and increased the foam's density and thermal stability. Still, the increase in basalt content reduced the burning time of the foams, indicating enhanced properties as a flame retardant and self-extinguishing capacity compared to traditional foams.