Anodic alumina (AA) membranes are composed of highly uniform, nanometer-scale pores arranged in a hexagonal close-packed array. Depositing conformal films inside the nanopores is extremely difficult because have an ultrahigh aspect ratio L/d ≈ 103. Atomic layer deposition (ALD) thin film growth technique that can deposit uniform on high-aspect-ratio substrates with monolayer thickness control. In this study, AA were coated Al2O3 and ZnO ALD subsequently analyzed using cross-sectional...

Abstract Defect‐free Pd membranes were prepared by an electroless plating technique on porous stainless‐steel tubes. The effective surface of was up to 75 cm 2 . helium flux not detected at room temperature and pressure difference 3 atm. At 350°C hydrogen permeances \documentclass{article}\pagestyle{empty}\begin{document}$ 8\ m^3 /(m^2 \cdot \overrightarrow h atm^{0.5}) $\end{document} obtained. A t a 1 atm 350°C, selectivity coefficients as high J(H /JN ) = 5,000 observed. Fluxes gases,...

The structure of hydroxylated alumina surface is analysed by IR spectroscopy. variety OH groups differing in number and coordination surrounding metal atoms, for the completely hydrated surface, either formed ideal low-index planes, or complicated crystal edges corners cation vacancies, restricted to six, but grows dramatically upon dehydroxylation. results account complex observed previously spectra after high-temperature treatment, enable us explain specific properties transition aluminas.

The electrode size dependence of the effective large signal piezoelectric response coefficient (d33,f) lead zirconate titanate (PZT) thin films is investigated by using double beam laser interferometer measurements and finite element modeling. experimentally observed shown to arise from a contribution substrate. intrinsic PZT d33,f independent equal theoretical value derived assuming rigid substrate strongly dependent on relative with respect thickness. For sizes larger than thickness,...

In a recently published paper [S. Sivaramakrishnan et al., Appl. Phys. Lett. 103, 132904 (2013)], the electrode-size dependence of longitudinal effective piezoelectric coefficient (d33,f) thin films measured by double beam laser interferometry was shown to be due substrate clamping effects. It also that true d33,f is when ratio electrode size thickness approximately unity, in case with isotropic elastic properties and Poisson's ∼0.3. this paper, we further investigate critical (rc) at which...

Lead-free Sr(Hf0.5Zr0.5)O3-modified Bi0.5(Na0.8K0.2)0.5TiO3 (SHZ-BNKT) ceramics were synthesized using a conventional solid-state, mixed-oxide method. In complex solid solutions such as BNKT, the role of ternary additive is important because it can break up long-range dipole order, which destabilizes ferroelectric phase leading to relaxor behavior. this system, verified by x-ray diffraction, SHZ was incorporated into BNKT perovskite lattice throughout studied compositional range. The...

Bulk ceramic 72.5 mol%( Bi 0.5 Na ) TiO 3 –22.5 K –5 mol% ( Mg Ti O BNT – BKT BM gT) has previously been reported to show a large high‐field piezoelectric coefficient d 33 * = 570 pm/V). In this work, the same composition was synthesized in thin film embodiments on platinized silicon substrates via chemical solution deposition. Overdoping of volatile cations precursor solutions necessary achieve phase‐pure perovskite. An annealing temperature 700°C resulted good ferroelectric properties P...

Abstract Niobium‐doped, {100} textured, gradient‐free, lead zirconate titanate ( PZT ) films were fabricated from solutions with different contents. Film content was controlled through changes in the average solution excess 14.7% to 17 at.%. The low field dielectric response as well polarization‐electric hysteresis loops not a strong function of content. However, lower contents precursor tended withstand higher poling fields than prepared more lead‐rich precursors. Although no residual PbO...

Abstract A Pb(Zr,Ti)O 3 (PZT) seed layer without Pb‐deficient defective areas was developed to improve the dielectric breakdown strength and lifetime of thin film piezoelectric actuators. The proportion area in layers reduced by adjusting amount Pb excess solution, combined with implementation a dense, large‐grained (>200 nm) Pt bottom electrode. optimal solution about 20 at%; seeding improved when slightly Ti‐rich composition (relative morphotropic phase boundary) utilized. It found that...

Abstract Thin films based on PbZr 1− x Ti O 3 and K Na NbO are increasingly being commercialized in piezoelectric MEMS due to the comparatively low drive voltages required relative bulk actuators, as well facile approach making sensor or actuator arrays. As these materials incorporated into devices, it is critically important that they operate reliably over lifetime of system. This paper discusses some factors controlling electrical electromechanical reliability lead zirconate titanate...

Abstract Direct seeding of {001} textured lead zirconate titanate ( PZT ) on platinized silicon substrates was achieved by chemical solution deposition. The processing space for texturing explored, under fixed pyrolysis and crystallization conditions, varying the content in solution, dopant species, layer thicknesses deposition Si with different platinum grain sizes. Strong texture fine‐grained (25 nm) deposited at room temperature dense, large‐grained (80 elevated temperature. Increases...

Abstract A series of niobium‐doped, {100} textured, “gradient free,” lead zirconate titanate ( PNZT ) films with different PbO contents were fabricated by the chemical solution deposition method. The films’ content was controlled changing average in from 114.7 to 117 at.%. During dielectric breakdown process 1.5 μm thick Pt top and bottom electrodes, two phenomena observed: cracking thermal piezoelectric film. At 150°C, an applied 400 kV/cm electric field, crack density induced...

Piezoelectric microelectromechanical systems (piezoMEMS) enable dense arrays of actuators which are often driven to higher electrical fields than their bulk piezoelectric counterparts. In ceramics, high field driving causes internal heating the piezoelectric, largely due field-induced domain wall motion. Self-heating is then tracked as a function vibration velocity determine upper bound for drive levels. However, literature limited concerning self-heating in thin film piezoMEMS. this work,...

A comparison has been made of the effectiveness smoothing and differentiating Savitzky-Golay filters in terms minimization total error criterion. The advantages multipassing based on quartic/quintic (for smoothing) cubic/quartic differentiation) polynomials have proved. generalized method is proposed for choice polynomial length, both filters, fine-structure analysis composite spectra. This follows suggestion P. Gans G. B. Gill to locate an inflection point curve variance residuals between...

A novel method of fabricating nanodimensional multilayer films using electrochemistry is described. thin layer tantalum (Ta) sputtered on a smooth insulating substrate. Ta partially electrochemically oxidized (anodized) forming Ta2O5 layer. The rate consumption, the expansion, and dependence thickness anodization conditions have been carefully characterized to enable accurate predictions resulting thicknesses both layers. Due strong planarization action process, interfaces Ta/Ta2O5...

The motion of domain walls in lead zirconate titanate (PZT) produces both nonlinearity and hysteresis. While measurements the resulting self-heating under an electric field drive are well known bulk ferroelectric ceramics, effects PZT films may differ from those ceramics due to a combination reduced wall motion, differences heat dissipation associated with substrates or passive elastic layers, typical fields. Here, it is shown that thermal imaging test structures piezoelectric...

Accurate and reliable measurements of piezoelectric coefficients on thin films are required to perform film process development compare different manufacturing techniques quality especially in MEMS applications.

When utilizing double-beam laser interferometry to assess the piezoelectric coefficient of a film on substrate, probing both top and bottom sample surfaces is expected correct erroneous bending contribution by canceling additional path length from height change. However, when deformation becomes extensive uncontrolled, as in case membranes or fully released films, setup can no longer account for artifacts, thus resulting inflated displacement data implausibly large values. This work serves...