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A. B. Kozyrev - One of the best experts on this subject based on the ideXlab platform.

  • Efficiency of thermoelectric conversion in Ferroelectric film capacitive structures
    Technical Physics, 2012
    Co-Authors: V. A. Volpyas, A. B. Kozyrev, O. I. Soldatenkov, E. R. Tepina
    Abstract:

    Thermal heating/cooling conditions for metal-insulator-metal structures based on barium strontium titanate Ferroelectric Films are studied by numerical methods with the aim of their application in capacitive thermoelectric converters. A correlation between the thermal and capacitive properties of thin-film Ferroelectric capacitors is considered. The time of the temperature response and the rate of variation of the capacitive properties of the metal-insulator-metal structures are determined by analyzing the dynamics of thermal processes. Thermophysical calculations are carried out that take into consideration the real electrical properties of barium strontium titanate Ferroelectric Films and allow estimation of thermal modulation parameters and the efficiency of capacitive thermoelectric converters on their basis.

  • Electronically switchable bulk acoustic wave resonator based on paraelectric state Ferroelectric Films
    Electronics Letters, 2011
    Co-Authors: A. B. Kozyrev, S. V. Ptashnik, A.k. Mikhaylov, S.v. Zinoviev, P.k. Petrov, N.m. Alford, T. Wang
    Abstract:

    The electromechanical properties of multilayer microwave capacitance structures with two Ferroelectric Films in the paraelectric state are analysed. A film bulk acoustic wave resonator (FBAR) with about two times (approximately octave) resonance frequency switching is demonstrated. The switching phenomenon is due to the application of a unidirectional or oppositely directed DC control E-field to Ferroelectric layers that results in the excitation of different acoustic eigenmodes in the resonator structure.

  • Switchable bulk acoustic wave resonator based on Ferroelectric Films
    2010 20th International Crimean Conference "Microwave & Telecommunication Technology", 2010
    Co-Authors: A. K. Mikhailov, S. V. Ptashnik, A. B. Kozyrev
    Abstract:

    The calculation of eigen acoustic modes of multilayer microwave capacitance structure with thin Ferroelectric Films in paraelectric state is carried out. For estimation of excitation efficiency of bulk acoustic waves (BAW) by Ferroelectric Films the system of electromechanical equations is solved and spatial distribution of mechanical displacements in the structure is presented. Finally, the switch ability of eigen acoustic modes for novel switchable BAW resonator is discussed.

  • Ferroelectric Films at high microwave power of ka-band frequency
    Integrated Ferroelectrics, 2006
    Co-Authors: A. B. Kozyrev, V. N. Keis, O. Buslov, A. Ivanov, T. B. Samoilova, O. I. Soldatenkov, V. E. Loginov, Andrey Tumarkin, L. Sengupta
    Abstract:

    Abstract This paper presents the experimental and modeling results on microwave (∼37 GHz) investigations of SrTiO3 and (Ba,Sr)TiO3 Ferroelectric Films at high levels of microwave power. The Ferroelectric film planar varactors were incorporated into the fin-line. The threshold microwave power leading to the appreciable variation in the microwave response of the tunable structure was determined. Thermal conditions of the varactors under test were analyzed. Thermal time constant and overheating of the Ferroelectric Films were estimated. The dependence of the varactor overheating on geometry was studied. Design optimization possibilities for the varactors in high microwave power applications are discussed.

  • Procedures of Measurements of Ferroelectric Films Parameters in Frequency Range (20–60) GHz
    Integrated Ferroelectrics, 2003
    Co-Authors: A. B. Kozyrev, V. N. Keis, P.v. Kulik, I.v. Kotelnikov, O. Buslov, D.p. Dovgan, Louise C. Sengupta, Luna H. Chiu, B. Treadway, T. Kaydanova
    Abstract:

    Two measuring procedures for characterization of Ferroelectric Films in K-U-band frequency ranges are presented: electrodeless measurements of Ferroelectric film parameters based on quasi-optical resonator and method based on measurements of self-resonance of Ferroelectric varactor.

Paul Muralt - One of the best experts on this subject based on the ideXlab platform.

  • The emancipation of Ferroelectricity
    Nature Materials, 2007
    Co-Authors: Paul Muralt
    Abstract:

    Contrary to bulk materials, high-resolution microscopy of ultra-thin Ferroelectric Films finds only a weak coupling of polarization down to unit-cell dimensions. The established theoretical picture can be resurrected by the inclusion of epitaxial strain effects.

  • Piezoelectric thin film for {MEMS}
    Ingrated Ferroelectrics, 1997
    Co-Authors: Paul Muralt
    Abstract:

    Thin film piezoelectric materials offer a number of advantages in microelectromechan-ical systems (MEMS), due to the large motions that can be generated, often with low hysteresis, the high available energy densities, as well as high sensitivity sensors with wide dynamic ranges, and low power requirements. This chapter reviews the literature in this field, with an emphasis on the factors that impact the magnitude of the available piezoelectric response. For non-Ferroelectric piezoelectrics such as ZnO and AlN, the importance of film orientation is discussed. The high available electrical resistivity in AlN, its compatibility with CMOS processing, and its high frequency constant make it especially attractive in resonator applications. The higher piezoelectric response avail-able in Ferroelectric Films enables lower voltage operation of actuators, as well as high sensitivity sensors. Among Ferroelectric Films, the majority of the MEMS sensors and actuators developed have utilized lead zirconate titanate (PZT) Films as the transducer. Randomly oriented PZT 52/48 Films show piezoelectric e 31,f coefficients of about −7 C/m 2 at the morphotropic phase boundary. In Ferroelectric Films, orientation, composi-tion, grain size, defect chemistry, and mechanical boundary conditions all impact the observed piezoelectric coefficients. The highest achievable piezoelectric responses can be observed in {001} oriented rhombohedrally-distorted perovskites. For a variety of such Films, e 31,f coefficients of −12 to −27 C/m 2 have been reported. 200 Electroceramic-Based MEMS: Fabrication-Technology and Applications

C. Dunn - One of the best experts on this subject based on the ideXlab platform.

L. Sengupta - One of the best experts on this subject based on the ideXlab platform.

  • Ferroelectric Films at high microwave power of ka-band frequency
    Integrated Ferroelectrics, 2006
    Co-Authors: A. B. Kozyrev, V. N. Keis, O. Buslov, A. Ivanov, T. B. Samoilova, O. I. Soldatenkov, V. E. Loginov, Andrey Tumarkin, L. Sengupta
    Abstract:

    Abstract This paper presents the experimental and modeling results on microwave (∼37 GHz) investigations of SrTiO3 and (Ba,Sr)TiO3 Ferroelectric Films at high levels of microwave power. The Ferroelectric film planar varactors were incorporated into the fin-line. The threshold microwave power leading to the appreciable variation in the microwave response of the tunable structure was determined. Thermal conditions of the varactors under test were analyzed. Thermal time constant and overheating of the Ferroelectric Films were estimated. The dependence of the varactor overheating on geometry was studied. Design optimization possibilities for the varactors in high microwave power applications are discussed.

  • nonlinear response and power handling capability of Ferroelectric baxsr1 xtio3 film capacitors and tunable microwave devices
    Journal of Applied Physics, 2000
    Co-Authors: A. B. Kozyrev, A. Ivanov, T. B. Samoilova, O. I. Soldatenkov, K Astafiev, L. Sengupta
    Abstract:

    The nonlinear response of Ferroelectric BaxSr1−xTiO3 Films to microwave electric field intensity up to ∼3×106 V/m was studied. Two techniques were used for this investigation: (i) 10 GHz pulsed power measurements, and (ii) 4 GHz intermodulation distortion (IMD) measurements. The nonlinear distortion of the resonant curve under microwave pulsed power and generation of the third-order IMD products in microwave resonators using Ferroelectric film planar capacitors were measured. The use of microwave pulses and continuous signals enabled the separation of the nonlinear dielectric response from the heating response of the Ferroelectric Films and the microwave nonlinear parameters of the Ferroelectric Films to be determined. It is shown that up to a specified value of microwave voltage amplitude the nonlinear response of BaxSr1−xTiO3 film capacitors can be predicted from the small signal capacitance–voltage characteristics. Formulas to estimate power handling capability connected with the field dielectric nonlinearity and the film overheating are derived for the tunable microwave devices based on Ferroelectric Films.The nonlinear response of Ferroelectric BaxSr1−xTiO3 Films to microwave electric field intensity up to ∼3×106 V/m was studied. Two techniques were used for this investigation: (i) 10 GHz pulsed power measurements, and (ii) 4 GHz intermodulation distortion (IMD) measurements. The nonlinear distortion of the resonant curve under microwave pulsed power and generation of the third-order IMD products in microwave resonators using Ferroelectric film planar capacitors were measured. The use of microwave pulses and continuous signals enabled the separation of the nonlinear dielectric response from the heating response of the Ferroelectric Films and the microwave nonlinear parameters of the Ferroelectric Films to be determined. It is shown that up to a specified value of microwave voltage amplitude the nonlinear response of BaxSr1−xTiO3 film capacitors can be predicted from the small signal capacitance–voltage characteristics. Formulas to estimate power handling capability connected with the field dielectric nonli...

S. Aggarwal - One of the best experts on this subject based on the ideXlab platform.

  • Empirical model for fatigue of PZT Ferroelectric memories
    2002 IEEE International Reliability Physics Symposium. Proceedings. 40th Annual (Cat. No.02CH37320), 2002
    Co-Authors: J. Rodriguez, S. Aggarwal, J. Mcpherson, T. Moise, S. Summerfelt, K.r. Udayakumar, S. Gilbert, C. Dunn
    Abstract:

    Switched polarization fatigue was investigated for CVD PZT Ferroelectric Films of thickness

  • Near-field second-harmonic microscopy of thin Ferroelectric Films
    Quantum Electronics and Laser Science Conference (QELS 2000). Technical Digest. Postconference Edition. TOPS Vol.40 (IEEE Cat. No.00CH37089), 2000
    Co-Authors: I.i. Smolyaninov, H.y. Liang, C.c. Davis, S. Aggarwal, R. Ramesh
    Abstract:

    Summary form only given. We present a near-field optical technique for second harmonic imaging using bare tapered optical fiber tips illuminated with femtosecond laser pulses. We show theoretically and experimentally that under illumination with P-polarized light the local SHG from the sample region under the tip is strongly enhanced even in the case of a dielectric tip. At the same time, the glass tip itself does not generate any measurable SH light. The local SH emission from the sample region under the tip is collected by the same tapered fiber which has a field of view on the order of the half of the wavelength of SH: light /spl lambda//sub 2/spl omega///2 in diameter, where /spl lambda//sub 2/spl omega//=400 nm (this is the resolution limit of a linear near-field microscope using bare tapered fibers). This configuration automatically solves one of the main problems in apertureless near-field microscopy: rejection of the background signal from the entire illuminated sample area. As a result, a spatial resolution of the order of 80 nm has been achieved in imaging of thin Ferroelectric Films.

  • Room temperature thin film Ba/sub x/Sr/sub 1-x/TiO/sub 3/ Ku-band coupled microstrip phase shifters: effects of film thickness, doping, annealing and substrate choice
    1999 IEEE MTT-S International Microwave Symposium Digest (Cat. No.99CH36282), 1999
    Co-Authors: F.w. Van Keuls, S. Aggarwal, R. Ramesh, C.h. Mueller, F.a. Miranda, R.r. Romanofsky, C.l. Canedy, T. Venkatesan, J.s. Horwitz, W. Chang
    Abstract:

    We report on measurements taken on thirteen Ku-band coupled microstrip phase shifters (CMPS) using thin Ferroelectric Films of Ba/sub x/Sr/sub 1-x/TiO/sub 3/. This CMPS design is a recent innovation designed to take advantage of the high tunability and tolerate the high dielectric constant of Ferroelectric Films at Ku- and K-band frequencies. These devices are envisioned as a component in low-cost steerable beam phased array antennas. Comparisons are made between devices with differing film thickness, annealed vs. unannealed, Mn-doped vs. undoped, and also substrates of LaAlO/sub 3/ and MgO.