Optical interferometric displacement detection techniques have recently found use in the study of nanoelectromechanical systems (NEMS). Here, we effectiveness these as relevant NEMS dimensions are reduced beyond optical wavelength used. We first demonstrate that cavities formed sacrificial gaps subwavelength enable enhanced sensitivity. In a second set measurements, show sensitivity conventional path-stabilized Michelson interferometry degrades rapidly diffraction limit. Both experiments...

Abstract A moving edge of a small mechanical structure, closely placed in front photodetector, can offer an easy means monitoring its motion via the optical knife-edge effect. Here, we present detailed analysis this nanomechanical detection scheme, which miniaturized device to be probed also serves as effective knife edge. Especially modulation generated from expected structure well corresponding sensitivity is considered by analytical and numerical modeling along with experimental...

We describe an optical knife-edge technique for nanomechanical displacement detection. Here, one carefully focuses a laser spot on moving edge and monitors the reflected power as is displaced sideways. To demonstrate detection using technique, we have measured in-plane resonances of nanometer scale doubly clamped beams. The obtained sensitivity in ∼1pm∕Hz range—in close agreement with simple analytical model.

Reliable operation of a miniaturized mechanical system requires that nanomechanical motion be transduced into electrical signals (and vice versa) with high fidelity and in robust manner. Progress transducer technologies is expected to impact numerous emerging future applications micro- and, especially, nanoelectromechanical systems (MEMS NEMS); furthermore, high-precision measurements are broadly used study fundamental phenomena physics biology. Therefore, development transducers sensitivity...

Optical interferometry has found recent use in the detection of nanometer scale displacements nanoelectromechanical systems (NEMS). At reduced length NEMS, these measurements are strongly affected by diffraction light. Here, we present a rigorous numerical model optical interferometric displacement NEMS. Our combines finite element methods with Fourier optics to determine electromagnetic field near-field region NEMS and propagate this detector far field. The noise analysis based upon allows...

Here, we demonstrate the pressure-sensing scheme based on photothermal effect in miniaturized beam resonator moderate pressure range. Since resonance frequency of small under thermal stress can be easily modulated by convective cooling gas molecules, change has been monitored tracking shift constant optical power. Our experimental measurements as well analytical model show that described technique ensures fast response to external variation with high responsivity much sought-after...

Monodispersed Fe3−xMnxO4 (x = 0, 0.25, 0.5, 0.75, and 1.0) microspheres were prepared by a solvothermal reaction method. Field emission scanning electronmicroscope (FESEM) high resolution transmission electron microscope (HRTEM) measurements showed that the size of monodispersed particles was around 200 ∼ 400 nm, with single crystalline spots in selected-area diffraction (SAED) patterns. From detailed Rietveld refinement analysis, crystal structure determined to be cubic spinel lattice...

Lithium iron silicate compounds of Li2FeSiO4 and partially delithiated Li2−xFeSiO4 (x = 0.66) were synthesized by vacuum-sealed solid-state chemical delithiation reactions, their magnetic properties characterized based on Mössbauer analysis. Crystal structures both are found to be γs-type (P21/n) monoclinic with difference in the lattice parameters due lithium delithiation. spectrum below TN1 20 K exhibits eight Lorentzians Fe2+ antiferromagnetic ordering. However, intermediate compound...

We have studied the temperature dependent magnetic properties and crystalline phase transitionn in small amount Fe doped nickel chromite. The Crystalline structure of <TEX>$NiCr_{1.7}Fe_{0.3}O_4$</TEX> is spinel cubic (Fd-3m) with a lattice constant <TEX>$a_0=8.317\AA$</TEX> at room temperature. <TEX>$N\acute{e}el$</TEX> <TEX>$(T_N)$</TEX> chromite sample determined to be 250 K. <TEX>$M\ddot{o}ssbauer$</TEX> spectra exhibit that there are two phases different sites for <TEX>$Cr^{3+}$</TEX>...

We describe the photothermal effect in an aluminium–silicon nitride doubly-clamped beam with optical deflection scheme. Incident power results temperature rise composite and shift resonance frequency due to thermal stress. The observed dynamic response is consistent detailed equation as well conduction model. pressure-dependent dynamics of allows investigation convective heat dissipation surrounding gas molecules determination transfer coefficient. photothermally coupled operation presented...

We report a novel full-color display based on the generation of by blue light approach, so called color-by-blue display. This newly proposed light-valve combines backlight excitation source, shutter, and front-emitting phosphor pixels. Careful evaluation shows that detailed characteristics as well excellent cycling durability under low operation voltage 3 V easily satisfy requirements for current application. Also, we would like to emphasize method conversion efficiency 20%, surpassing value...

Gaussian fluctuations (or noise) appear in almost all measurements physics. Here, a concise and self-contained introduction to thermal noise is presented. Our analysis the frequency domain centers on of position particle bound one-dimensional harmonic potential, which this case microcantilever immersed bath room-temperature gas. Position microcantilever, detected by optical beam deflection technique, are then fed into lock-in amplifier measure probability distribution spectral properties...

We present transport and tunneling measurements of Pb-Ag bilayers with thicknesses, ${d}_{\mathrm{P}\mathrm{b}}$ ${d}_{\mathrm{A}\mathrm{g}}$, that are much less than the superconducting coherence length. The transition temperature, ${T}_{c}$, energy gap, $\ensuremath{\Delta}$, in density states (DOS) decrease exponentially ${d}_{\mathrm{A}\mathrm{g}}$ at fixed ${d}_{\mathrm{P}\mathrm{b}}$. Simultaneously, a DOS increases linearly from Fermi grows introduces within gap. integrated subgap...

We describe the operation of a phase-locked loop (PLL) that tracks high-frequency electromechanical resonance nanoscale beam resonator. The fundamental in-plane flexural resonator embedded in PLL is actuated electrostatically and detected optically. demonstrated by locking stably to frequency beam, tracking this with high fidelity as mass loaded. Our analysis reproduces observed behavior. Feedback control schemes for nanoelectromechanical resonators may offer prospects miniature timekeeping...

The charge ordering effect in LuFe2O4 powder is investigated with the vibrating sample magnetometer and Mössbauer spectroscopy. crystal structure of shows two-dimensional layered type rhombohedral(R3¯m) structure. lattice constants are found to be a0=3.439Å c0=25.258Å by Rietveld refinement. Néel temperature (TN) determined 250K. spectra consist four sextets indicating magnetic below TN, where three sets assumed Fe3+ phases other Fe2+ at 4.2K, two doublets splitting a paramagnetic region. At...

We have fabricated quasi-two-dimensional disordered arrays of nanoscale Pb grains coupled by an overlayer Ag grains. Their temperature-dependent resistive transitions follow predictions for array mesoscopic superconductor--normal-metal--superconductor junctions. The decrease their transition temperatures with thickness systematically deviates from the Cooper limit theory proximity effect as grain size decreases. deviations occur when estimated number pairs per is $&lt;1$ and suggest approach...

We report the microscopic evidence for magnetic and structural phase transitions in multiferroic spinel FeV2O4 from hyperfine interaction. sample shows three different crystal structures with tetragonal to orthorhombic structure around 70 K, 109 cubic 140 K. Mössbauer spectra of FeV2O4, obtained at various temperatures, were analyzed severely distorted 8-line below TC, doublet TC. Also, change singlet TJT ≅ K due reduction Jahn-Teller effect. The value electric quadrupole splitting (ΔEQ) is...

We have synthesized magnetic Fe-doped NiGa2S4 and investigated its electrical properties with a superconducting quantum-interference device magnetometer, Mössbauer spectroscopy, physical property measurement system. X-ray diffraction analysis at room temperature shows that the prepared samples are single phase trigonal structure (P-3m1). From zero-field-cooled (ZFC) field-cooled magnetization curves under 100 Oe between 4.2 200 K, we measured temperature-dependent susceptibility χ of...

We have investigated the evolution of sheet resistance thin nickel films, thermally evaporated on porous alumina substrates, based in situ electron transport measurement. By comparing having various surface area fractions, to uniform film, following scaling law metal-insulator transition, we been able describe growth and resulting thickness-dependent film light two-dimensional percolation model. The underlying pore array strongly affects appearance conductance, study suggests possibility...

The (K,Na)NbO3 (KNN)-based ceramics have been deemed one of the most promising lead-free piezoelectric materials replacing lead-containing ones. In our study, we prepared both undoped and Mn-doped KNN nanofibers via electrospinning method investigated how thermal annealing process affects their structural, crystallographic, properties. X-ray diffraction measurements suggest that crystallization occurs around 450°C in these fibers, with increasing temperature, become granular small grains...

The effect of proton irradiation on magnetic properties lithium ferrites has been investigated with x-ray diffraction (XRD), magnetization, and Mössbauer spectroscopy measurements. Li0.5Fe2.5O4 powders have fabricated by the sol-gel method. Following annealing at 700 °C, these samples irradiated 1, 5, 10 pC/μm2. analysis XRD patterns Rietveld refinement method shows that ordered cubic spinel structures space group P4332. We observed corresponding lattice constant a0 linearly increases from...