J.-Z. Ruan

East China Normal University, Shanghai, Shanghai Shi, China

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Publications (20)16.63 Total impact

  • X.-Q. Pan · X. Li · H.-L. Pan · Q. Zhao · J.-Z. Ruan · X.-F. Ji · D.-L. Chen · Z.-J. Zhao
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    ABSTRACT: In this work, Cu/SiO2 and Cu/SiO2/Ni80Fe20 composite wires were prepared by RF magnetron sputtering on the rotating substrate of Cu. The influence of the rotating rates during sputtering SiO2 on the microstructure and giant magnetoimpedance (GMI) effect of the composite wires was investigated by the methods of SEM and impedance analyzer. The results showed that with the increase of the rotating rate, the particle size of the film surface first decreased and then increased, while the GMI effect of the Cu/SiO2/Ni80Fe20 composite wires first increased and then decreased.
    No preview · Article · May 2014 · Gongneng Cailiao/Journal of Functional Materials
  • R. L. Wang · X. Li · X. H. Kong · Y. X. Guo · J. Z. Ruan · Z. J. Zhao
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    ABSTRACT: Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance (GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 kHz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ΔR/R and magnetoinductance ratio ΔX/X make the comparative contributions to the total magnetoimpedance (MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.
    No preview · Article · Apr 2013 · Nano-Micro Letters
  • D. L. Chen · Z. J. Zhao · L. Jiang · J. Z. Ruan · X. L. Yang
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    ABSTRACT: In this paper, a new method for fabricating Ni80Fe20/Cu composite wires is presented. A series of samples were prepared by alternating the rotating direction of the Cu wire during RF magnetron sputtering. In order to keep the overall coating thickness of all the samples constant, the alternating intervals and rotating period of each sample during sputtering were varied. As the rotating period increased, the samples showed different magneto-impedance profiles. Experimental results indicated that there was a critical thickness for single sputtered layer which the MI ratio was significantly enhanced at a relatively low driven current frequency. Qualitative discussion on these phenomena was explained in terms of exchange interaction and electromagnetic interactions.
    No preview · Article · Dec 2011 · Surface Review and Letters
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    ABSTRACT: In this work, Ni80Fe20/Cu composite wires of length 50 mm, consisting a Cu core of diameter 100 μm, coated with a layer of Ni80Fe20, were produced by RF magnetron sputtering. To obtain a uniform coating, the wires were spun during sputtering by a homemade system. The results showed that the spinning speed might affect the maximum MI ratio and the magnetic properties. The MI ratio of the sputtered wires increases with the wire spinning speed in the magnetron sputtering. The film thickness had a significant effect on the magnitude and the optimum frequency of the giant magneto-impedance effect. The maximum MI ratio can reach about 247.4% for the specimen with a Ni80Fe20 coating thickness of 2.81 μm at 400 kHz. This large MI effect, obtained at such low frequency range, was correlated with the electromagnetic interaction between the inner core and the magnetic coating.
    No preview · Article · Dec 2008 · Surface Review and Letters
  • J.-K. He · W.-Z. Yuan · J.-K. Cheng · H.-L. Pan · J.-Z. Ruan · C.-M. Wang
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    ABSTRACT: By controlling the process conditions, the CoP/Insulator/BeCu composite wires have been prepared by electroless-deposition on polyester-coated BeCu wires. The as-deposited sample was treated with current annealing. The composite wire constructs complicated LCR reasonant circuit by itself. It was observered that an impedance change of 80.0% at 60 MHz caused by analogic parallel resonance. Due to the analogic serial resonance, the maximum GMI ratio reaches 793.1% at 79.6 MHz, which is much higher than ordinary sample's GMI value at the same frequence. By using the equivalent circuit, this complicated reasonant GMI phenomenon and reasonant point was analyzed. Their results agree well with each other.
    No preview · Article · Nov 2008 · Gongneng Cailiao/Journal of Functional Materials
  • L. Jiang · L.S. Tan · J.Z. Ruan · W.Z. Yuan · X.P. Li · Z.J. Zhao
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    ABSTRACT: In this work, magnetron sputtering in the form of continuous deposition or intermittent deposition modes was used to obtain NiFe/Cu composite wires. Based on the results, intermittent deposition mode led to the formation of an interface between deposited layers. A better crystallite and a little grain growth were found for the intermittently deposited wire. Good soft magnetic properties and large giant magneto-impedance (GMI) effect were exhibited by both composite wires. The GMI profile for the intermittently deposited composite wire was characterized by two peaks, which could be attributed to the difference in the magnetic properties of the inner and the outer magnetic layers. Annealing was introduced to the intermittently deposited wire so that the inherent stresses were partially relaxed. As a result, its GMI effect was enhanced and the magnetic properties of the two magnetic layers became similar. Hysteresis loops of the composite wires displayed different magnetic behaviors and hence further affirmed the GMI results.
    No preview · Article · Sep 2008 · Physica B Condensed Matter
  • X. Li · Q. Zhang · J.-Z. Ruan · Q.-J. Wang · X.-L. Yang · Z.-J. Zhao
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    ABSTRACT: A comparative study between conventional giant magnetoimpedance sensor and off-diagonal giant magnetoimpedance sensor using Co-based amorphous wire as sensing element has been investigated. Under the dc external magnetic field the output signals of these two sensors have been measured with the length of sample varying. The influence of demagnetization field and other factors have been also discussed. The results show that off-diagonal sensor has some advantages of high sensitivity, which increases a little with the sample length decreasing, and non-hysteresis. It shows great potential for weak magnetic field detection, which provides some references for the minimization of magnetic sensors.
    No preview · Article · Jul 2008 · Chinese Journal of Sensors and Actuators
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    ABSTRACT: CoP/Insulator/BeCu composite wire incorporating a capacitor was prepared by chemical deposition. This new type of composite wire functions as an LC resonance circuit element by itself, in which large LC resonance giant magneto-impedance (LCR-GMI) effect was observed when the driving frequency approached to the LC resonance frequency. The properties of LCR-GMI in the composite wire with a length of 9.5 cm were investigated. Its LCR-GMI ratio and field sensitivity are 487.5% and 0.46 % /A · m-1 at the resonance frequency of 29 MHz, respectively, which are higher than those of the ordinary composite wire. When the carrier frequency deviates from the resonance frequency, LCR-GMI ratio decreases obviously, showing distinct selectivity of frequency. Meanwhile, we proposed an equivalent circuit model based on the characteristics of the LC resonance composite wire, and simulated the experimental curves. The simulation results agreed well with the experimental data. Using the equivalent circuit model, we analyzed the physical mechanisms of LCR-GMI and the influence of wire length on the LCR-GMI effect.
    No preview · Article · May 2008
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    ABSTRACT: By controlling the process conditions the CoP/Insulator/BeCu composite wires with distinct giant magneto-impedance effect (GMI) have been prepared by electroless-deposition on polyester-coated BeCu wires. The as-deposited sample was treated with current annealing. A dramatic increase of the GMI value was observed at a low frequency after current annealing. The maximum GMI ratio reaches about 991% and the field sensitivity a-mounts to 2.78%/(A·m-1) at 97 kHz, The GMI value is above 50 K at the frequency range from 3 kHz to 30 MHz. The properties of magnetization processes for the annealed samples are analyzed via the complex permeability. The real and imaginary part of the complex permeability change significantly with the variation of DC magnetic field after current annealing.
    No preview · Article · Nov 2007 · Gongneng Cailiao/Journal of Functional Materials
  • R.-L. Wang · Z.-J. Zhao · W.-Z. Yuan · J.-Z. Ruan · X.-L. Yang
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    ABSTRACT: Using electroless deposition, the composite wires with ferromagnetic core and conductive core were produced. The properties of GMI were investigated, the composite wires with ferromagnetic core obtained the maximum 107% at f = 60MHz, and the composite wires with BeCu core obtained the maximum 108% at f = 300kHz. An obvious MR effect is observed in the CuBe/insulator/NiCoP composite wires at lower frequency, then R and X make comparative contribrtion to the total MI ratio. The results show that MI ratio is dependent not only on the values of and but also on the ratio between R and X, so the obvious MI effect can be observed not only soft magnetic properties but also lower resistivity.
    No preview · Article · Oct 2007 · Gongneng Cailiao/Journal of Functional Materials
  • X.Z. Wang · W.Z. Yuan · X.D. Li · J.Z. Ruan · Z.J. Zhao · J.X. Yang · X.L. Yang · Z. Sun
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    ABSTRACT: CuBe/NiFeB and CuBe/Insulator/NiFeB composite wires have been prepared by electroless-deposition. The giant magnetoimpedance (GMI) effect for NiFeB layer with thickness of 3μm on CuBe core with diameter of 100μm has been studied. After adding an insulator layer, the maximal GMI ratio of CuBe/Insulator/NiFeB composite wire is much higher than that of CuBe/NiFeB composite wire, and can reach to about 250% at the frequency range of 500kHz–1MHz. The results are explained in terms of difference of magnetic structure and different frequency dependence of resistance and reactance of the two kinds of composite wires.
    No preview · Article · Jan 2007 · Journal of Magnetism and Magnetic Materials
  • Q.-M. Mao · J.-Z. Ruan · Q.-J. Wang · X.-L. Yang · Z.-J. Zhao
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    ABSTRACT: The Cu/FeNi composite-wires were prepared by RF magneto-sputter equipment in this paper. The investigation of magnetic properties and giant magnetic impendence effect of wires were presented. The results show that Cu/FeNi composite-wires possess better soft magnetic properties. The maximum of MI ratio reaches 247.4% at a low frequency and the FeNi coating thickness has great influence on soft magnetic-properties of the wires. We find the optimum thickness. When the coating thickness is big enough, the magnetic moments direction of the magnetic film are orientated from the initial circumferential direction to the longitudinal direction. Hence, we concluded there are different GMI behaviors in the composite wires.
    No preview · Article · Jan 2007 · Gongneng Cailiao/Journal of Functional Materials
  • R.-L. Wang · Z.-J. Zhao · W.-Z. Yuan · J.-Z. Ruan · G.-D. Hu · X.-L. Yang
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    ABSTRACT: Composite wires CuBe/insulator/NiCoP of 60 mm insulated CuBe core coated with a layer of Ni57Co38P5 were produced by electroless deposition, and their magnetic properties were studied. The results showed that a good magneto-impedance effect can be obtained at relatively low frequency. The magneto-impedance effect was observed even at 1 kHz, it reaches -3.32%. The maximum GMI ratio of composite wire reached 108% at 300 kHz. In order to improve the soft magnetic properties, then, the samples were annealed at 200°C in N2 atmosphere. The influence of magnetic layer thickness on GMI was also investigated. The study showed that MI ratio is dependent not only on the value of ΔR/R and ΔX/X but also on the ratio between R and X.
    No preview · Article · Jan 2007 · Gongneng Cailiao/Journal of Functional Materials
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    ABSTRACT: The giant magneto-impedance and skin effect in electroless deposited CuBe/CoNiP composite wires with different diameter of CuBe core are presented, and involves a theoretical approach of the current density distributions in layers. Results show that the strong eddy current in the magnetic CoNiP coating will be induced due to the electromagnetic interactions with the CuBe core. It makes the skin effect strong in the magnetic coating even at very low frequency, and at this, large MI changes can also be observed.
    No preview · Article · Oct 2006 · Journal of Magnetism and Magnetic Materials
  • X D Li · W Z Yuan · Z J Zhao · J Z Ruan · X L Yang
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    ABSTRACT: The giant magneto-impedance (GMI) effect in nanocrystalline FeCuNbSiB multilayered films was investigated. The multilayered films were deposited by magnetron sputter equipment with an additional SiO2 outer layer. The GMI ratio of multilayered films varied with the annealing temperature due to the changing orientation of the magnetic moments. The maximum GMI frequency of the nanocrystalline state was lower than that of the amorphous state, decreasing from 12.3 to 5.45 MHz. Ageing experiments were carried out for films with and without the insulator layer. It was seen that the GMI ratio of the multilayer film with a covered SiO2 layer was preserved well even after ageing.
    No preview · Article · Apr 2005 · Journal of Physics D Applied Physics
  • X.-D. Li · W.-Z. Yuan · Z.-J. Zhao · J.-Z. Ruan · X.-L. Yang
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    ABSTRACT: The giant magneto-impedance (GMI) effect was investigated in the nanocrystalline FeCuNbSiB multilayered films in the present paper. The results indicate that the maximum LMI ratio was 44% at the frequency of 3 MHz, and the maximum TMI ratio was 46% at the frequency of 6 MHz, respectively. The TMI spectra have a threshold field. While the magnetic field is bigger than the threshold field, the magneto-impedance was evidently decreased. In the nanocrystalline multilayered films, the frequency of the maximum LMI ratio is lower than its amorphous multilayered film. The GMI ratio of multilayered films was changed following the orientation of magnetic moments. When the orientation of moments was perpendicular to the film plane, the GMI ratio was dramatically decreased.
    No preview · Article · Dec 2004 · Gongneng Cailiao/Journal of Functional Materials
  • X. D Li · W. Z Yuan · Z. J Zhao · X. Z Wang · J. Z Ruan · X. L Yang
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    ABSTRACT: The investigation of the nanocrystallization and magnetic properties of FeCuNbSiB films by X-ray diffraction (XRD) and Mössbauer spectrum is presented in this paper. The XRD results showed that the films begin to crystallize at 400°C. The nanocrystalline volume fraction of the samples and the orientation of the magnetic moments could be obtained by the Mössbauer spectrum. From as-deposited state to the sample annealed at 570°C, the magnetic moments of the films were orientated from the initial direction parallel to the film plane to the direction perpendicular to it, and later back. Eventually, moments orientations of the film samples were random. The magnetic studies also revealed the moments orientations during the heat treatment. The giant magneto-impedance (GMI) ratio of sandwiched films varies with changing orientation of magnetic moments. When the orientation of moments was perpendicular to the film plane, the GMI ratio decreased dramatically.
    No preview · Article · Aug 2004 · Journal of Magnetism and Magnetic Materials
  • Source
    Z.J. Zhao · Y.Z. Fang · J.Z. Ruan · X.L. Yang
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    ABSTRACT: Resonance frequency f r of a LC circuit composed of a capacitor and a small solenoid, which contains Fe-based nanocrystalline powder cores, was measured. The properties of resonance frequency f r shift dependence on external magnetic field, H ex ; have been investigated. The results showed that f r evidently increases with H ex and exhibits good linearity and sensitivity in the low field range. The large frequency shift is another form of giant magneto-impedance effect. The method can be used for measuring magnetic field or for improving the sensitivities of magnetic sensors. r 2003 Elsevier B.V. All rights reserved.
    Preview · Article · Jul 2004 · Journal of Magnetism and Magnetic Materials
  • L.-P. Liu · Z.-J. Zhao · J.-Z. Ruan · T. Chen · R.-L. Wang · X.-L. Yang
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    ABSTRACT: Amorphous Fe73.0Cu1.0Nb1.5 V2.0Si13.5B9.0 microwires were prepared using glass-coating melt-spinning method, and nanocrystalline microwires were obtained after annealing amorphous microwires at appropriate temperatures. The magnetic properties and giant magneto-impedance (GMI) effect were also investigated. It showed that the microwires exhibits the best soft magnetic properties and the largest magneto-impedance MI% ratio, about 253%, in the samples after annealing between 540°C and 570°C and at 570°C respectively.
    No preview · Article · Dec 2003 · Gongneng Cailiao/Journal of Functional Materials
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    L. Zeng · Z.J. Zhao · X.L. Yang · J.Z. Ruan · G. Chen
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    ABSTRACT: The giant magneto-impedance (GMI) effect for Fe73.5Cu1Nb3Si13.5B9 nanocrystalline ribbons is investigated in the temperature range between room temperature and 873 K. The thermal dependence of GMI effect reveals the enhancement of Curie temperature of the amorphous matrix, reflecting the exchange coupling between the α-FeSi grains as well as the compositional changes of the amorphous matrix itself. However, the dipolar interaction between grains is suggested to be responsible for the non-zero GMI effect after the magnetic phase transition of the amorphous matrix.
    Preview · Article · May 2002 · Journal of Magnetism and Magnetic Materials