Nanomaterials for the adsorptive treatment of Hg(II) ions from water

Getting the books piezoelectricity an introduction to the theory and applications of electromechanical phenomena in crystals now is not type of inspiring means. You could not by yourself going next book buildup or library or borrowing from your contacts to door them. This is an definitely simple means to specifically get lead by on-line. This online pronouncement piezoelectricity an introduction to the theory and applications of electromechanical phenomena in crystals can be one of the options to

Piezoelectricity An Introduction to the Theory and Applications of Electromechanical Phenomena in Crystals

This article presents the annealing effect on the structural, elastic, thermodynamic, optical, magnetic, and electric properties of Ni0.6Zn0.4Fe1.5Al0.5O4 (NZFAO) nanoparticles (NPs). The samples were successfully synthesized by the sol–gel method followed by annealing of the as-synthesized at 600, 800, 900, 1050, and 1200 °C. This approach yielded the formation of a highly crystalline structure with crystallite size ranging from 17 nm to 40 nm. X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, as well as energy disperse spectroscopy (EDS), Fourier transform infrared (FTIR) and Raman spectroscopy, were used in order to determine the structural and morphological properties of the prepared samples. Rietveld XRD refinement reveals that Ni–Zn–Al ferrite nanoparticles crystallize in inverse cubic (Fdm) spinel structure. Using FTIR spectra, the elastic and thermodynamic properties were estimated. It was observed that the particle size had a pronounced effect on elastic and thermodynamic properties. Magnetic measurements were performed up to 700 K. The prepared ferrite samples present the highest Curie temperature, which decreases with increasing particle size and which is consistent with finite-size scaling. The thickness of the surface shell of about 1 nm was estimated from size-dependent magnetization measurements using the core–shell model. Besides, spin resonance, magnetostriction, temperature coefficient of resistance (TCR), and electrical resistivity properties have been scientifically studied and appear to be different according to their size. The optical properties of synthesized NZFAO nanoparticles were investigated, and the differences caused by the particle sizes are discussed on the basis of the phonon confinement effect. This effect was also inspected by the Raman analysis. Tuning of the physical properties suggests that the Ni–Zn–Al ferrite samples may be promising for multifunctional diverse applications.

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Magnetic and spectroscopic properties of Ni–Zn–Al ferrite spinel: from the nanoscale to microscale

In the last decade, research on the synthesis and characterization of nanosized ferrites has highly increased and a wide range of new applications for these materials have been identified. The ability to tailor the structure, chemical, optical, magnetic, and electrical properties of ferrites by selecting the synthesis parameters further enhanced their widespread use. The paper reviews the synthesis methods and applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanoparticles, with emphasis on the advantages and disadvantages of each synthesis route and main applications. Along with the conventional methods like sol-gel, thermal decomposition, combustion, co-precipitation, hydrothermal, and solid-state synthesis, several unconventional methods, like sonochemical, microwave assisted combustion, spray pyrolysis, spray drying, laser pyrolysis, microemulsion, reverse micelle, and biosynthesis, are also presented. MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanosized ferrites present good magnetic (high coercivity, high anisotropy, high Curie temperature, moderate saturation magnetization), electrical (high electrical resistance, low eddy current losses), mechanical (significant mechanical hardness), and chemical (chemical stability, rich redox chemistry) properties that make them suitable for potential applications in the field of magnetic and dielectric materials, photoluminescence, catalysis, photocatalysis, water decontamination, pigments, corrosion protection, sensors, antimicrobial agents, and biomedicine.

Recent Advances in Synthesis and Applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) Nanoparticles

https://cyberleninka.org/article/n/410744.pdf

Structural and Magnetic Properties of Ultrafine CoFe2O4 Nanoparticles

This paper reports on electromechanical, switching time and performance analysis of capacitive shunt RF MEMS switch with uniform and non-uniform meanders. The MEMS switch is a freely moving membrane over coplanar wave guide. Electromechanical analysis is done for movable beam with gold as material and dielectric as Si3N4 and HfO2. For these dielectric materials pull in voltage is 2.3 and 2 V respectively with beam thickness of 0.8 µm by using COMSOL FEM Tool. Si3N4 with dielectric constant of 7.6 gives Cratio of 8.69 and 11.13 for 0.8 and 0.6 μm of beam thickness respectively. RF performance analysis is done by using HFSS software and the simulation results states that non uniform single meander has return loss as −60 dB, insertion loss −0.2 dB and isolation loss −14 dB at 20 GHz frequency and uniform 3 meander switch has return loss as −55 dB. Switching time analysis is done by using MATLAB. For uniform three meander it is 0.12 ms and for non-uniform one meander beam it is 0.7 ms. Whereas use of HfO2 with dielectric constant of 14 as dielectric gives Cratio of 14.93 and 19.66 for 0.8 and 0.6 μm of beam thickness respectively with gap between the electrode beam and dielectric as 0.8 μm.

Analysis of RF MEMS shunt capacitive switch with uniform and non-uniform meanders

Controlled phase evolution and the occurrence of single domain CoFe 2 O 4 nanoparticles synthesized by PVA assisted sol-gel method

In this paper, we have designed, simulated, fabricated, and characterized a clamped-clamped micro mechanical structure-based shunt capacitive RF MEMS switch. The clamped–clamped micromechanical structure is micromachined using a gold metal thickness of 500 nm. AlN is used as a dielectric material, and it is deposited using the dc sputtering PVD process. In the MEMS technology, particularly in devices fabrication, releasing the membrane is a difficult task, and here, we have presented a novel wet process to release the membrane. Primarily, the S1813 sacrificial layer is etched by using the piranha solution and cleaned with the IPA solution. Critical point drying is done after fabrication to reduce the stiction effect on the switch. Overall, the switch requires the pull-in voltage of 5.5 V for 1.8- $\mu \text{m}$ displacement. In the process of optimization, primarily, the switch is designed and simulated using finite-element method tools. The reliability of the capacitive RF MEMS switches depends on the stiction problem caused by dielectric charging, and the proposed capacitive switch dielectric charging behavior is characterized using the CV curve method.

Fabrication and Characterization of Capacitive RF MEMS Perforated Switch

This paper is about, the design and analysis of shunt capacitive RF MEMS switch with less actuation voltage, low insertion losses and high isolation losses. The switch design is incorporated the El...

Design and analysis of CPW based shunt capacitive RF MEMS switch

In this paper, a micro level electrostatically actuated cantilever and metal contact based series RF MEMS Switch is designed and analyzed using Finite Element Method Tool. The designed switch is simulated and the performance is verified over the frequency range 0.8–20 GHz. In investigation, it is noticed that the performance of the RF MEMS Switch is decided by the actuation voltage, insertion losses, isolation losses and reliability. The switch designed in this paper achieved a constant insertion losses of −0.08 to −0.14 dB, isolation losses of −58 to −20 dB. This work also concentrated on the cantilever actuation voltage, and it is reduced to 3.55 V by using less weight polymer material like Poly Tetra Fluoro Ethylene (PTFE). The series metal contact based electrostatically driven switching is created in Microstrip Transmission line using cantilever structure associated with gold contact material. The designed RF MEMS switch is preferable in the design and implementation of reconfigurable communi...

K. Srinivasa Rao

Papers

Analysis of RF MEMS shunt capacitive switch with uniform and non-uniform meanders

Controlled phase evolution and the occurrence of single domain CoFe 2 O 4 nanoparticles synthesized by PVA assisted sol-gel method

Fabrication and Characterization of Capacitive RF MEMS Perforated Switch

Design and analysis of CPW based shunt capacitive RF MEMS switch

A micro level electrostatically actuated cantilever and metal contact based series RF MEMS switch for multi-band applications