The dielectric and piezoelectric behavior of 70Pb(Mg1/3Nb2/3)O-3-30PbTiO(3) (70PMN-30PT) thin films was studied as a function of lateral scaling. Dense PMN-PT films 300-360 nm in thickness were prepared by chemical solution deposition using a 2-methoxyethanol solvent. These phase pure and strongly {001} oriented films exhibited dielectric constants exceeding 1400 and loss tangents of approximately 0.01. The films showed slim hysteresis loops with remanent polarizations of about 8 mu C/cm(2) and breakdown fields over 1500 kV/cm. Fully clamped films exhibited large signal strains of 1%, with a d(33,f) coefficient of 90 pm/V. PMN-PT films were patterned down to 200 nm in spatial scale with nearly vertical sidewalls via reactive ion etching. Upon lateral scaling, which produced partially declamped films, there was an increase in both small and large signal dielectric properties, including a doubling of the relative permittivity in structures with width-to-thickness aspect ratios of 0.7. In addition, declamping resulted in a counterclockwise rotation of the hysteresis loops, increasing the remanent polarization to 13.5 mu C/cm(2). Rayleigh analysis, Preisach modeling, and the relative permittivity as a function of temperature were also measured and further indicated changes in the domain wall mobility and intrinsic response of the laterally scaled PMN-PT.

A single beam laser interferometer based on a modified Mirau detection scheme with a vertical resolution of 5 pm was developed for localized d33 measurements on patterned piezoelectric films. The tool provides high spatial resolution (2 lm), essential for understanding scaling and processing effects in piezoelectric materials. This approach enables quantitative information on d33, currently difficult in local measurement techniques such as piezoresponse force microscopy. The interferometer is built in a custom microscope and employs a phase lock-in technique in order to detect sub-Angstrom displacements. d33 measurements on single crystal 0.67PbMg0.33Nb0.67O3-0.33PbTiO3 and bulk PbZrTiO3-5A ceramics demonstrated agreement within <3% with measurements using a double beam laser interferometer. Substrate bending contributions to out-of-plane strain, observed in thin continuous PbZr0.52Ti0.48O3 films grown on Si substrates is reduced for electrode diameters smaller than 100 lm. Direct scanning across room temperature and 150 C poled 5 lm and 10 lm features etched in 0.5 lm thick PbZr0.52Ti0.48O3 films doped with 1% Nb confirmed minimal substrate contributions to the effective d33,f. Furthermore, enhanced d33,f values were observed along the feature edges due to partial declamping from the substrate, thus validating the application of single beam interferometry on finely patterned electrodes.

TEXT: The information age challenges computer technology to process an exponentially increasing computational load on a limited energy budget 1-3 -a requirement that demands an exponential reduction in energy per operation. In digital logic circuits, the switching energy of present FET devices is intimately connected with the switching voltage [3][4][5] , and can no longer be lowered sufficiently, limiting the ability of current technology to address the challenge. Quantum computing offers a leap forward in capability 6 , but a clear advantage requires algorithms presently developed for only a small set of applications. Therefore, a new, general purpose, 2 classical technology based on a different paradigm is needed to meet the ever increasing demand for data processing.A promising pathway to fast, low voltage classical devices is transduction which is widely used in nature to propagate signals in bioorganisms 7 . When propagating digital logic, we require the input and output signal to be electronic -however, this still allows for an intermediate form In this work we present two physical realizations of the PET concept on an early developmental pathway leading to the fully integrated PET of Fig. 1. The two devices are evolved to generate stress and accomplish an IMT in the PR channel -key for demonstrating the viability of the PET concept. The first approach, Gen-0, uses a millimeter-scale piezoelectric 4 actuator to compress a 50 nm thick PR film, metallize the channel and cycle the transition at kHz frequencies. The second, Gen-1, uses a micron scale, lithographed, piezoelectric pillar to compress a nanoscale, e-beam patterned PR element, enabling cycling at 100-kHz frequencies.The Gen-0 PET generates the stress required to drive an insulator-metal transition in a 50 nm SmSe 18 film where the conducting area is defined by a hole in a silicon nitride layer, as shown in Fig. 2a. A microindenter is utilized as a yoke to provide the counter force against which a commercial piezoelectric actuator compresses and activates conductivity in the SmSe. In operation, a 1 kHz sine wave applied to the actuator with a 20 Vp-p (peak-to-peak) amplitude generates a displacement, resulting in a force on the SmSe element. An On/Off modulation of over three orders of magnitude in PR resistance is generated as illustrated in Fig. 2b Fig. 2b). The Gen-0 PET frequency response is bounded by actuator resonance to 1 kHz (note the small phase shift, due to the mechanical delay, between the applied actuator voltage and the PR response), a limitation removed in the Gen-1 device which employs an integrated micro-actuator.Demonstrating a device with a micro-actuator providing only nanometer sized displacement is key for establishing the viability of the PET concept. The Gen-1 PET, illustrated in Fig. 3a-b, addresses this important challenge. The micro-actuators, fabricated on an 8" silicon wafer, are PE pillars (approximately 2×2×1 µm 3 ), contacted by long leads running on top of patterned PE.Each micro-actuator is flanked by a PE mesh us...

Dielectric and piezoelectric properties for Zn1-xMgxO (ZMO) thin films are reported as a function of MgO composition up to and including the phase separation region. Zn1-xMgxO (0.25 ≤ x ≤ 0.5) thin films with c-axis textures were deposited by pulsed laser deposition on platinized sapphire substrates. The films were phase pure wurtzite for MgO concentrations up to 40%; above that limit, a second phase with rocksalt structure evolves with strong {100} texture. With increasing MgO concentration, the out-of-plane (d33,f) and in-plane (e31,f) piezoelectric coefficients increase by 360% and 290%, respectively. The increase in piezoelectric coefficients is accompanied by a 35% increase in relative permittivity. Loss tangent values fall monotonically with increasing MgO concentration, reaching a minimum of 0.001 for x ≥ 0.30, at which point the band gap is reported to be 4 eV. The enhanced piezoelectric response, the large band gap, and the low dielectric loss make Zn1-xMgxO an interesting candidate for thin film piezoelectric devices, and demonstrate that compositional phase transformations provide opportunities for property engineering.