Publications by Paul Muralt | EPFL Graph Search

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Integrated optical devices can be fabricated by the deposition of an electrode/piezoelectric/electrode multilayer thin film structure onto optical fibers, The particular structure used in this work is Au/PbTiO3/Pt/Ti, where the PbTiO3 is deposited by DC reactive magnetron sputtering at high temperature to obtain in situ crystallised perovskite structure. Preliminary studies showed that the deposition temperature and the relative fluences of the Pb and Ti species are determining parameters for the growth of

Ultrasonic motors for low electrical power applications are considered for portable devices such as an electronic wristwatch. For the study of a standing wave type motor, a modular approach was proposed, where stators and rotors are added in an assembly step. The mode conversion principle called the 'elastic fin motor' and its extension to an 'elastic force motor' suitable for a flat profile motor are discussed. Fabrication methods and the mechanical response of silicon diaphragms covered by PZT (PbZrxTi1-x

We present the fabrication of 570-mu m-thick millimeter-sized soda-lime-silicate float-glass blocks with a 1-mu m-thick AlN thin-film piezoelectric transducer sandwiched between thin metallic electrodes and deposited on the top surface. The electromechanic ...

This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-mu m-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus par ...

This paper presents the electrical characterizations of a novel concept for thermal energy harvesting at micro scale. The devices presented here are based on a two-step transduction combining thermo-mechanical and piezoelectric conversion. The piezoelectri ...

In this work, the potential of magnetron sputtered magnesium fluoride (MgF2) and MgF2 containing composite coatings for coloured solar collector glazing is investigated. Coloured thin-film interference coatings on the reverse side of the collector cover glass give solar collectors an aesthetic appearance, which facilitates their integration into the building’s envelope. Hereby, integration means that the solar collector is no longer recognisable as technical device. Moreover, its appearance is the one of an

Complex oxides show extreme sensitivity to structural distortions and defects, and the intricate balance of competing interactions which emerge at atomically defined interfaces may give rise to unexpected physics. In the interfaces of non-magnetic complex ...

Sputter deposited A1ScN films with an Sc content of 38 at % were investigated by X-ray diffraction and electron microscopy to study the influence of the radio frequency (RF) bias on the growth of abnormally oriented grains (AOG). Scanning electron microsco ...

A solid oxide fuel cell structure obtainable by selective electrochemical processing, comprising an electrolyte membrane (4) formed by a thin film more than 50nm but less than l0[mu]m thick, covering a supporting structure (1) made of a bulk substrate, the ...

The accurate evaluation of ferroelectric thin films operated with interdigitated electrodes is quite a complex task. In this article, we show how to correct the electric field and the capacitance in order to obtain identical polarization and CV loops for a ...

Micro-scale solid oxide fuel cell is a promising power generation technology for portable devices such as laptop, medical devices and personal electronics. One of the key goals in design of μ-SOFC systems is to use common hydrocarbon fuels such as propane/butane, which requires an additional micro-scale gas-processing unit (GPU) to reform the fuel, avoiding the coking on the μ-SOFC membranes. However, no integrated micro-fabricated testing platform has been reported for evaluating the stability, thermal man

The CaCu3Ti4O12 (CCTO) thin films were deposited on Pt/TiO2/Ti/SiO2/Si (100) substrates by pulsed laser deposition. The temperature dependences of dielectric constant were measured in the as-produced thin film samples, showing the so-called colossal dielectric constant (CDC) phenomenon. I-V and C-V characterizations evidenced that the electrode interface formed a Schottky barrier, whose depletion capacitance resulted in the observed CDC in CCTO thin films, while the interior of the material was found to be

Pb(Zr, Ti)O-3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetr

The use of interdigitated electrodes (IDEs) in conjunction with ferroelectric thin films shows many attractive features for piezoelectric MEMS applications. In this work, growth of {1 0 0}-textured lead zirconate titanate (PZT) thin films was achieved on i ...

A ceramic-based, meso-scale fuel processor for on-board production of syngas fuel was demonstrated for applications in micro-scale solid-oxide fuel cells (mu-SOFCs). The processor had a total dimension of 12 mm x 40 mm x 2 mm, the gas reforming micro react ...

Novel, highly sensitive piezoelectric acoustic sensors based on partially unclamped Pb(Zr-x, Ti1-x)O-3 (PZT) coated cantilever and bridge have been fabricated by silicon micromachining. High sensitivity at low frequencies (5-100 Hz) has been achieved by patterning very narrow slits (3 to 5 mum) around the structures. A typical response of 100 mV Pa-1 and a noise equivalent pressure of 1.6 mPa Hz(1/2) at 20 Hz have been measured using a 10 pF charge amplifier. Stress compensation, dry etching and integration

Several bottom electrode systems for ferroelectric thin film deposition onto reactive substrates or reactive metal films have been investigated with respect to chemical barrier properties and contact resistivity. Such electrode systems should not deteriorate by oxidation, and should prevent oxygen diffusion into the underlying base metal. First, the protective performance of Pt, Ru, RuO2/Ru, and Cr has been evaluated on reactive substances such as W, Zr, Mo, and TiN; On most materials, a reactive and passiv

The integration of piezoelectric Pb(Zr,Ti)O-3 thin films on silicon substrates for ultrasonic motor applications is reviewed. With suitable buffer and bottom electrode layers the problems due to high processing temperatures in oxygen ambient can be handled. Reproducibility can be increased by stabilized electrode systems and seeding layers for PZT nucleation. Elastic fin micromotors of millimeter size have been fabricated. They achieve the necessary torques, low speeds, and battery voltage operation for app

Highly textured PZT(111), PZT(001/100) and random PZT films have been grown on Pt and RuO2 bottom electrodes by means of an in-situ, multimagnetron reactive sputtering process with three metal targets (Pb, Zr, Ti). The orientation was varied with the bottom electrode/PZT initial interlayer deposition conditions. Series of 300 nm thick films with varying composition x have been prepared. The Ti and Zr ratio was changed by adjusting the powers of the corresponding targets. The lead content was self stabilized

Paul Muralt

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A micro heater platform with fluid channels for testing micro-solid oxide fuel cell components

Influence of the deposition temperature and Pb species flux on the characteristics of PbTiO3 thin films deposited by sputtering on optical fibers

Flexural-standing-wave elastic force motor using ZnO and PZT thin film on micromachined silicon membranes for wristwatch applications

Fabrication, Characterization, and Simulation of Glass Devices with AlN Thin-Film Transducers for Excitation of Ultrasound Resonances

Piezoelectric micromachined ultrasonic transducers based on PZT thin films

Electrical characterization of a buckling thermal energy harvester

Potential of magnetron sputtered magnesium fluoride containing thin films for the multilayer design of coloured coatings for solar collector glazing

The emergence of magnetic ordering at complex oxide interfaces tuned by defects

Impact of negative bias on the piezoelectric properties through the incidence of abnormal oriented grains in Al0.62Sc0.38N thin films

Metallic supporting grid for ultrathin electrolyte membranes in solid oxide fuel cells

Characterization methodology for lead zirconate titanate thin films with interdigitated electrode structures

Design, Fabrication and Characterization of a Gas Processing Unit Testing Platform for Micro-Solid Oxide Fuel Cells

On origin and intrinsic electrical properties of the colossal dielectric constant state in CaCu3Ti4O12

Dielectric and acoustical high frequency characterisation of PZT thin films

Converse mode piezoelectric coefficient for lead zirconate titanate thin film with interdigitated electrode

A low-temperature co-fired ceramic micro-reactor system for high-efficiency on-site hydrogen production

Piezoelectric Pb(Zr-x,Ti1-x)O-3 thin film cantilever and bridge acoustic sensors for miniaturized photoacoustic gas detectors

Conducting barriers for direct contact of PZT thin films on reactive substrates

Ultrasonic micromotors based on PZT thin films

Piezoelectric and dielectric properties of sputter deposited (111), (100) and random-textured Pb(ZrxTi1-x)O-3 (PZT) thin films