Browsing by Author "Zhuang, Xin"

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    Estimation of the Intrinsic Power Efficiency in Magnetoelectric Laminates Using Temperature Measurements
    Zhuang, Xin; Leung, Chung Ming; Li, Jiefang; Viehland, Dwight D. (MDPI, 2020-06-11)
    Magnetoelectric (ME) power efficiency is a more important property than the ME voltage or the current coefficients for power conversion applications. This paper introduces an analytical model that describes the relation between the external magnetic field and the power efficiency in layered ME composites. It is a two-phase model. The first fragment establishes the expression between the magnetic field strength and the temperature increase within an operating period. It uses a magneto-elasto-electric equivalent circuit model that was developed by Dong et al. Following previous investigations; the main loss source is the mechanical power dissipation. The second fragment links the power efficiency and the temperature increase in a heat-balanced system. This method is generally used by researchers in the piezoelectric field. The analytical model and the experimental data shows that the decrease of the power efficiency in a laminated composite is between 5% and 10% for a power density of 10 W/in3 (0.61 W/cm3) to 30 W/in3 (1.83 W/cm3). The failure mechanism/process of ME composites under high power density can be estimated/monitored by the proposed method for ME composites in practical applications.
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    A Low Frequency Mechanical Transmitter Based on Magnetoelectric Heterostructures Operated at Their Resonance Frequency
    Xu, Junran; Leung, Chung Ming; Zhuang, Xin; Li, Jiefang; Bhardwaj, Shubhendu; Volakis, John; Viehland, Dwight D. (MDPI, 2019-02-19)
    Magneto-elasto-electric (ME) coupling heterostructures, consisting of piezoelectric layers bonded to magnetostrictive ones, provide for a new class of electromagnetic emitter materials on which a portable (area ~ 16 cm2) very low frequency (VLF) transmitter technology could be developed. The proposed ME transmitter functions as follows: (a) a piezoelectric layer is first driven by alternating current AC electric voltage at its electromechanical resonance (EMR) frequency, (b) subsequently, this EMR excites the magnetostrictive layers, giving rise to magnetization change, (c) in turn, the magnetization oscillations result in oscillating magnetic fields. By Maxwell’s equations, a corresponding electric field, is also generated, leading to electromagnetic field propagation. Our hybrid piezoelectric-magnetostrictive transformer can take an input electric voltage that may include modulation-signal over a carrier frequency and transmit via oscillating magnetic field or flux change. The prototype measurements reveal a magnetic dipole like near field, demonstrating its transmission capabilities. Furthermore, the developed prototype showed a 104 times higher efficiency over a small-circular loop of the same area, exhibiting its superiority over the class of traditional small antennas.
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    Magnetoelectric nonlinearity in magnetoelectric laminate sensors
    Shen, Liangguo; Li, Menghui; Gao, Junqi; Shen, Ying; Li, Jiefang; Viehland, Dwight D.; Zhuang, Xin; Sing, M. Lam Chok; Cordier, Christophe; Saez, Sebastien; Dolabdjian, Christophe (American Institute of Physics, 2011-12-01)
    A nonlinearity in the magnetoelectric coefficient, alpha(Nonlin)(ME), of Metglas/Pb(Zr,Ti)O(3) (PZT) and Metglas/Pb(Mg(1/3),Nb(2/3))O(3)-PbTiO(3) (PMN-PT) laminate sensors has been observed. This nonlinearity was found to be dependent on the dc magnetic bias (H(dc)) and frequency of the ac drive field (H(ac)). The maximum value of alpha(Nonlin)(ME) for both types of composites was found near the electromechanical resonance. For Metglas/PZT laminates, the maximum occurred under a finite bias of H(dc) approximate to 5 Oe; whereas, for Metglas/PMN-PT, the maximum was found near zero dc bias. One application for alpha(Nonlin)(ME) is a cross-modulation scheme that can shift low frequency signals to higher frequency to achieve lower noise floor. For Metglas/PMN-PT, alpha(Nonlin)(ME) has another application: removal of the necessity of a dc bias, which helps to design high-sensitivity sensor arrays and gradiometers. (C) 2011 American Institute of Physics. [doi:10.1063/1.3665130]
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    Theoretical analysis of the intrinsic magnetic noise spectral density of magnetostrictive-piezoelectric laminated composites
    Zhuang, Xin; Cordier, Christophe; Saez, Sebastien; Sing, M. Lam Chok; Dolabdjian, Christophe; Gao, Junqi; Li, Jiefang; Viehland, Dwight D. (American Institute of Physics, 2011-06-15)
    The equivalent magnetic noise spectral density level for long type magnetostrictive-piezoelectric laminated composites has been investigated by using a 1D equivalent circuit model, and exemplified for a longitudinal-transverse mode. The theoretical developments explain well our experimental results. The findings show that similar ultimate magnetic noise spectral noise density can be expected whether using either charge or voltage amplifier detection methods. The findings show that a volume effect and the dielectric loss factor of the piezoelectric layer are the dominant sources of the noise floor. Our findings show that the noise scales as 1/root f. The lowest equivalent noise floor value that has been observed is 10/root f pT/root Hz for f << 10 kHz, with a white noise level of 100 fT/root Hz above 10 kHz. (C) 2011 American Institute of Physics. [doi:10.1063/1.3594714]