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Owing to the interesting physical characteristics of perovskites, herein, we investigate RbZnX3 (X = Cl, Br) halide perovskites for sustainable green energy applications. All the given structures were made relaxed and minimum energy was attained by employing Birch-Muranghan equation of state. The electronic band structure of the under study materials were calculated through modified-Beck-Johnson potential. Our results showed that all the investigated RbZnX3 (X = Cl, Br) perovskites are semiconductors with band gaps of 1.34, and 0.12 eV, respectively. The calculated tolerance factors, formation energies, Born-Hung criteria, phonon spectra and ab initio molecular dynamic (AIMD) simulations demonstrated that the given compounds exhibit geometrical, thermodynamic, mechanical, dynamic and thermal stabilities. Findings of elastic investigation revealed an elastic, anisotropic, and ductile nature of our predicted compounds. Moreover, all the studied materials revealed strong absorption – 104 cm−1 in the visible and ultraviolet spectrum and the device absorption efficiency (%) was found comparable to other known reported materials. Overall, this study demonstrates that our simulated perovskites are suitable candidates for photovoltaic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Laser ablation technique has be used to synthesize cadmium oxide and tin CdO(1-x)Snx nanocomposites. The XRD characteristics of the sample revealed the crystalline phase and cubic structure of the CdO samples, whereas the CdO: Sn nanocomposites with the doping ratios of (5, 10, and 15%) showed good crystallinity with cubic and tendency to orthorhombic structures. The crystallite size found to be slightly increasing with the doping ratio and the obtained values range from 26 to 30 nm. The average diameter is also increasing with the doping and ranges from less than 80 nm to about 90 nm. AFM analysis showed that increasing Sn-doping ratio causes a drop of the average roughness to a minimum value of about 0.5 nm and then increases with the doping to nearly similar case of undoped CdO sample. Optical measurements of absorption, transmission, and reflection spectra exhibit plasmonic effect and show significant effect of Sn-doping on the level and peak position of all the spectra. The energy band-gap value is enhanced with the doping and reach its maximum value of 2.722 eV at 10% doping ratio. On the other hand, the electron concentration, carrier mobility, and resistivity showed significant enhancement with the doping ratio. The dielectric properties have also shown remarkable variations with noticeable shifts in the peak values toward the higher wavelength range. The characteristic bands of both pure CdO and Sn-doped nanocomposites were confirmed by Fourier transform infrared spectroscopy (FTIR). All analyses suggest that the Sn-doping ratio of 10% is the optimum ratio for enhanced effects of these nanocomposites. [ABSTRACT FROM AUTHOR]

Cobalt-doped potassium hexa-titanate (Cox:K2Ti6O13 (x = 0.05, 0.10, 0.15 mole%)) ceramics were synthesized by the solid-state reaction method. The XRD patterns confirmed single-phase development in a monoclinic symmetry of various samples, and they were used for different structural calculations of Cox:K2Ti6O13 ceramics. The dielectric constant, tanδ, electrical modulus, and ac conductivity of Co-doped K2Ti6O13 were studied in the temperature range of 100–500 °C. Anomalies were observed in graphs of the dielectric constant versus temperature, showing the transition phase in the studied samples. Dielectric peaks at transition temperature decreased with an increasing frequency, and the peaks shifted toward higher temperatures, illustrating the relaxation of the dielectric materials. The composition with x = 0.10 showed low dielectric loss and a higher dielectric constant and can be utilized for high-temperature dielectric material. Small doping of cobalt improved the ac conductivity of K2Ti6O13 ceramics due to the increase in the spin–phonon interaction and dominant electron hopping conduction; however, the conductivity diminished with substantial doping because of the contraction of the tunnel space and ambushing of conduction electrons. The uniqueness of this study is in the high dielectric optimization of lead-free ceramic Cox:K2Ti6O13 and the discovery of positive temperature coefficients of the resistivity of these ceramic samples. [ABSTRACT FROM AUTHOR]

In this study, the structural and magnetic properties of a series of functionalized Co100−xNix (x = 20, 30, 40, 50, 60, 80, 85) nanoparticles (NPs) were analyzed with the objective of attaining a high specific absorption rate (SAR). The magnetic nanoparticles (MNPs) obtained by ball milling at 1425 rpm lie in the range of 03–29 nm and are studied as potential candidates for magnetic fluid hyperthermia. Magnetic measurements show that all samples possess soft ferromagnetic properties with the reduction in the Curie temperature (TC) by Ni substitution in Co100−xNix alloys and by ball milling. The specific absorption rate (SAR) and specific loss power (SLP) obtained from magnetothermal measurements for powder and fluid samples lie in the range 4.4–83 W/g and 19–382 W/g, respectively, showing strong dependence on structural and magnetic properties. The SAR/SLP values as a function of the applied field at 425 kHz display a square dependence on the applied magnetic field below 165 Oe, which is expected for single domain ferromagnetic nanoparticles, but deviate from this at higher values of the applied field. We also obtained the effective anisotropy constant K e f f for ball-milled nanoparticles at 1425 rpm for 200, 300, and 500 min. within the framework of linear response theory, showing strong dependence on average crystallite size. Additionally, the toxicity of the prepared nanoparticles in the form of percentage hemolysis was controlled with oleic acid. [ABSTRACT FROM AUTHOR]