Ruzhong Zuo

Hefei University of Technology, Luchow, Anhui Sheng, China

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Publications (149)353.9 Total impact

  • Donggeng Zheng · Ruzhong Zuo ·
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    ABSTRACT: A pseudo-cubic to tetragonal phase transformation was found to be accompanied by a relaxor-normal ferroelectric phase transition in new perovskite-type (0.65 − x)Bi(Ni1/2Ti1/2)O3–0.35PbTiO3–xPb(Mg1/3Nb2/3)O3 ceramics. A morphotropic phase boundary was identified in the range of 0.4 < x < 0.6 where the maximum quasi-static d33 = 550 pC/N was achieved. However, a large-strain platform of ∼0.35% was generated under 6 kV/mm (dynamic d33* = 583 pm/V) within 0.15 ≤ x ≤ 0.4. Particularly, the d33* and the strain hysteresis were found to be closely related with the Pb(Mg1/3Nb2/3)O3 content, field magnitude and signal frequency. The temperature-dependent measurement demonstrated that enhanced electrostrains appeared not only near a freezing temperature Tf, but also near an ergodic to ferroelectric phase transition temperature Tfr, both of which are ascribed to a reversible field induced ergodic to ferroelectric phase transition. An interesting finding would be that more similar free energies between ergodic and ferroelectric phases near Tfr have brought about smaller driving fields and strain hysteresis but lower maximum strains.
    Journal of the European Ceramic Society 11/2015; 35(13):3485-3493. DOI:10.1016/j.jeurceramsoc.2015.05.033 · 2.95 Impact Factor
  • Jian Zhang · Ruzhong Zuo · Yang Wang · Shishun Qi ·
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    ABSTRACT: Li4Ti5(1+x)O12 (-0.15≤x≤0.10) ceramics were successfully prepared via a conventional solid state method. The phase evolution, sintering behavior and microwave dielectric properties were systematically studied. As x≥0, TiO2 appeared as a secondary phase. Single phase Li4Ti5O12 was obtained at x=-0.10 to -0.05 with a cubic spinel structure, belonging to Fd-3m space group. Another impurity Li2TiO3 arose at x=-0.15, probably resulting from the overmuch Ti vacancies in the structure. Highest εr (∼26) and Q×f (∼68000 GHz) were achieved in pure-phase Li4Ti5O12 (x=-0.10), because suitable excess lithium not only compensated for the volatilization of lithium but greatly promoted the sintering behavior. Moreover, with the help of TiO2, τf values of the ceramics within 0≤x≤0.10 were adjusted to near zero, accompanied with excellent microwave dielectric properties of εr=18∼24, Q×f∼10000 GHz. Furthermore, these samples were chemically compatible with Ag. Thus, the Li4Ti5(1+x)O12 (-0.15≤x≤0.10) ceramics could be promising medium permittivity materials in consideration of their low cost, low sintering temperature and superior properties.
  • Jian Zhang · Ruzhong Zuo ·
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    ABSTRACT: The Li2Zn(Ti1−xZrx)3O8 (x = 0–0.10) ceramics were synthesized by a conventional solid-state reaction method. The effects of Zr substitution for Ti on the phase composition, microstructure and microwave dielectric properties were systematically investigated. It was found that most of Zr existed in the form of ZrO2 as a secondary phase, accompanied with the appearance of some Ti vacancies in Li2ZnTi3O8 phase. Large matrix grains were significantly refined, especially at x = 0.07. Meanwhile, a greatly improved Q × f value was obtained by the promoted densification, which could be assigned to the more uniform grains and the non-stoichiometry resulting from some Ti vacancies in main phase. By comparison, εr decreased slightly and τf showed almost no changes with the increment of Zr content. Excellent microwave dielectric properties of εr = 25.4, Q × f = 122,000 GHz (7 GHz) and τf = −16 ppm/°C were achieved in the x = 0.07 composition after sintered at 1100 °C for 4 h.
    Journal of Materials Science Materials in Electronics 11/2015; 26(11). DOI:10.1007/s10854-015-3615-x · 1.57 Impact Factor
  • Donggeng Zheng · Ruzhong Zuo ·
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    ABSTRACT: A novel (0.67−x)BiFeO3–0.33BaTiO3–xBaZrO3 lead-free relaxor ferroelectric ceramic was developed by a solid-state reaction method. Measurements of temperature-dependent dielectric permittivity and the polarization/strain hysteresis loops demonstrated an obvious evolution of dielectric relaxor behavior at room temperature (RT) from nonergodic to ergodic states. A significantly enhanced electrostrain of ~0.37% at 7 kV/mm with a relatively small hysteresis of ~39% and a low-frequency sensitivity was found at x = 0.04, showing large potential for actuator applications. This was basically attributed to a rapid response of forward and backward switching between ergodic and ferroelectric phases owing to similar free energies and large local random fields.
    Journal of the American Ceramic Society 10/2015; DOI:10.1111/jace.13989 · 2.61 Impact Factor
  • Ruzhong Zuo · Feng Li · Jian Fu · Donggeng Zheng · Wanli Zhao · He Qi ·

    Journal of the European Ceramic Society 10/2015; DOI:10.1016/j.jeurceramsoc.2015.10.013 · 2.95 Impact Factor
  • Shishun Qi · Ruzhong Zuo · Zhaosheng Ma ·

  • Tianwen Zhang · Ruzhong Zuo · Chen Zhang ·
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    ABSTRACT: In this work, the (1 − x)Li3(Mg0.92Zn0.08)2NbO6–xBa3(VO4)2 (x = 0.1–0.35) ceramics were prepared via a conventional solid state reaction route. The phase composition, microstructure and microwave dielectric properties were investigated by an X-ray diffractometer (XRD), a scanning electron microscope and a network analyzer. The XRD results indicated that the Li3(Mg0.92Zn0.08)2NbO6 and Ba3(VO4)2 phases could well coexist without forming any secondary phases. The dielectric constant (ϵr) and quality factor (Q × f) values of the Li3(Mg0.92Zn0.08)2NbO6 ceramic decreased with the addition of Ba3(VO4)2 phase, however its temperature coefficient of resonant frequency (τf) value was improved significantly. Excellent microwave dielectric properties of ϵr ∼ 16.3, Q × f ∼ 50,084 GHz (at 8.64 GHz) and τf ∼ 1.5 ppm/°C were achieved for the x = 0.3 sample when sintered at 950 °C for 4 h. The chemical compatibility with Ag electrode indicated that the 0.7Li3(Mg0.92Zn0.08)2NbO6–0.3Ba3(VO4)2 composite ceramic would be a promising material for the low temperature cofired ceramic applications.
    Materials Research Bulletin 08/2015; 68. DOI:10.1016/j.materresbull.2015.03.022 · 2.29 Impact Factor
  • Yang Wang · Ruzhong Zuo · Jian Zhang · Shishun Qi · Tianwen Zhang ·
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    ABSTRACT: The influence of the addition of low-melting point Li2O-B2O3-SiO2 (LBS) on the sintering behavior and microwave dielectric properties of commercial 0.95MgTiO3-0.05CaTiO3 (95MCT) was systematically investigated by means of an X-ray diffractometer, a scanning electron microscope and a network analyzer. The results revealed that the addition of an appropriate amount of LBS enables the 95MCT composite ceramic to sinter in an obviously low sintering temperature, simultaneously leading to a more uniform and compact microstructure. Furthermore, favorable microwave dielectric properties of εr = 18.2, Qxf = 67,000 GHz (7.9 GHz), τf = −5.2 ppm/°C) were yielded in the 10 wt% LBS-doped 95MCT sample when sintered at 1025 °C for 4 h, indicating that LBS is an effective ternary firing agent when employed in 95MCT system. The relatively low sintering temperature together with acceptable microwave dielectric properties enable the composite ceramic to be a more potential alternative for the present patch antennas.
    Journal of Materials Science Materials in Electronics 07/2015; 26(7). DOI:10.1007/s10854-015-3008-1 · 1.57 Impact Factor
  • Donggeng Zheng · Ruzhong Zuo · Dongshuai Zhang · Yang Li ·
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    ABSTRACT: A novel lead-free relaxor ferroelectric ceramic of (0.67−x)BiFeO3–0.33BaTiO3–xBa(Mg1/3Nb2/3)O3 [(0.67−x)BF–0.33BT–xBMN, x = 0–0.1] was prepared by a solid-state reaction method. A relatively high maximum polarization Pmax of 38 μC/cm2 and a low remanent polarization Pr of 5.7 μC/cm2 were attained under 12.5 kV/mm in the x = 0.06 sample, leading to an excellent energy-storage density of W ~1.56 J/cm3 and a moderate energy-storage efficiency of η ~75%. Moreover, a good temperature stability of the energy storage was obtained in the x = 0.06 sample from 25°C to 190°C. The achievement of these characteristics was basically attributed to an electric field induced reversible ergodic to ferroelectric phase transition owing to similar free energies near a critical freezing temperature. The results indicate that the (0.67−x)BF–0.33BT–xBMN lead-free realxor ferroelectric ceramic could be a promising dielectric material for energy-storage capacitors.
    Journal of the American Ceramic Society 07/2015; 98(9). DOI:10.1111/jace.13737 · 2.61 Impact Factor
  • Jian Zhang · Ruzhong Zuo ·
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    ABSTRACT: Lyonsite-structured Li2Mg2(WO4)3 (LMW) ceramics with low loss were prepared via a conventional solid-state method. Synthesis process, microstructure and microwave dielectric properties of LMW were systematically investigated. The results indicated that higher calcination temperature and addition of excess Li effectively eliminated the secondary phase MgWO4, and pure orthorhombic LMW phase could be prepared at 900 °C for 4 h using an excess amount of 1 mol% Li2CO3. Optimum microwave dielectric properties of εr=8.2, Q×f=90,000 GHz (f=11.2 GHz), and τf=−52.4 ppm/°C were obtained when pure LMW was sintered at 800 °C for 2 h. Moreover, for the (1-x) LMW-xTiO2 samples, superior microwave properties of εr=12.2, Q×f=50,000 GHz (f=9.6 GHz) and especially a near-zero τf (−2.8 ppm/°C) could be achieved when the x=0.14 (in volume ratio) sample was sintered at 850 °C for 2 h.
    Materials Letters 05/2015; 158. DOI:10.1016/j.matlet.2015.05.111 · 2.49 Impact Factor
  • Chen Zhang · Ruzhong Zuo ·
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    ABSTRACT: The low-temperature sinterable microwave dielectric composites with compositions of (1−x)Ba2V2O7–xBa3(VO4)2 (x = 0.27–0.52, in volume fraction) were prepared by cofiring mixtures of pure-phase Ba2V2O7 and Ba3(VO4)2. The phase structure and grain morphology of the ceramics were studied by X-ray diffraction and field emission scanning electron microscopy. The results indicated that the two phases of Ba2V2O7 and Ba3(VO4)2 can well coexist at sintering temperatures owing to different crystal structures. The microwave dielectric properties of this system were strongly related to densification, packing fraction, and the volume ratio of Ba2V2O7 and Ba3(VO4)2. The quality factor Q × f values and temperature coefficients of the resonant frequency (τf) of the ceramics can be significantly boosted by adjusting the relative content of the two phases. Consequently, a high Q × f value of 71,700 GHz, a near-zero τf of −1.4 ppm/°C and a low dielectric constant εr of 11.4 were obtained for the x = 0.42 sample sintered at a low temperature of 875 °C for 4 h, which are superior to those of several available low-loss dielectrics. In addition, no evidence of chemical reaction between the ceramics and Ag was observed during the cofiring process, suggesting that the as-prepared composite ceramics are suitable for low-permittivity low temperature co-fired ceramic applications.
    Journal of Alloys and Compounds 02/2015; 622:362-368. DOI:10.1016/j.jallcom.2014.10.056 · 3.00 Impact Factor
  • Jian Fu · Ruzhong Zuo · He Qi · Chen Zhang · Jingfeng Li · Longtu Li ·
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    ABSTRACT: Lead-free (Na0.52K0.48)(Nb1−ySby)O3 (NKNSy) ferroelectric ceramics were reported to exhibit an ultrahigh electrostrain (dynamic d33* (=S/E) of 800–1100 pm/V) in a relatively low driving electric field range (1–4 kV/mm). As evidenced by in-situ synchrotron x-ray diffraction and dielectric measurements, the mechanism of generating large strains was ascribed to both the low-field induced reversible rhombohedral-monoclinic phase transition (1–2 kV/mm) and the enhanced domain switching (2–4 kV/mm) owing to the normal to relaxor phase transformation, which contribute to ∼62% and ∼38% of the total strain, respectively. The results indicate that the NKNSy compositions would have excellent potentials for applications of lead-free actuator ceramics.
    Applied Physics Letters 12/2014; 105(24):242903. DOI:10.1063/1.4904476 · 3.30 Impact Factor
  • Source
    Wanli Zhao · Ruzhong Zuo · Jian Fu ·
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    ABSTRACT: Large electrostrains (∼0.4% at 7 kV/mm) of the new (0.7 − x)Bi(Mg1/2Ti1/2)O3–xPb(Mg1/3Nb2/3)O3–0.3PbTiO3 ((0.7 − x)BMT–xPMN–0.3PT) ceramics with x = 0.0–0.7 near the morphotropic phase boundary of the BMT–PT–PMN ternary system were found to be associated with the evolution of the compositionally modulated dielectric relaxor behavior. As disclosed by in situ high-resolution synchrotron X-ray diffraction, more intermediate phases of different symmetries induced by external fields largely contribute to smaller strain hysteresis (∼23%) of PMN-rich compositions than BMT-rich ones. Particularly, the x = 0.2 sample exhibits temperature-insensitive electrostrains of ∼0.3% at 5 kV/mm varying less than 10% from room temperature up to 160 °C, which is mainly attributed to the coexistence of two kinds of relaxor states in a broad temperature range owing to special static domain structures typical for BMT-rich compositions. These findings provide a new approach toward an appropriate compositional design for low-hysteresis temperature-insensitive large electrostrains in BMT-based relaxor ferroelectrics.
    Journal of the European Ceramic Society 12/2014; 34(16):4235–4245. DOI:10.1016/j.jeurceramsoc.2014.07.017 · 2.95 Impact Factor
  • Yang Wang · Ruzhong Zuo · Chen Zhang · Jian Zhang · Tianwen Zhang ·
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    ABSTRACT: We report a series of ReVO4 (Re = La, Ce) microwave dielectric ceramics fabricated by a standard solid-state reaction method. X-ray diffraction and scanning electron microscopy measurements were performed to explore the phase purity, sintering behavior, and microstructure. The analysis revealed that pure and dense monoclinic LaVO4 ceramics with a monazite structure and tetragonal CeVO4 ceramics with a zircon structure could be obtained in their respective sintering temperature range. Furthermore, LaVO4 and CeVO4 ceramics sintered at 850°C and 950°C for 4 h possessed out-bound microwave dielectric properties: εr = 14.2, Q × f = 48197 GHz, τf = −37.9 ppm/°C, and εr = 12.3, Q × f = 41 460 GHz, τf = −34.4 ppm/°C, respectively. The overall results suggest that the ReVO4 ceramics could be promising materials for low-temperature-cofired ceramic technology.
    Journal of the American Ceramic Society 12/2014; 98(1). DOI:10.1111/jace.13378 · 2.61 Impact Factor
  • Tianwen Zhang · Ruzhong Zuo ·
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    ABSTRACT: The effect of Zn2+ substitution on the structure and microwave dielectric properties of Li3Mg2NbO6 ceramic was investigated. The compositions of Li3(Mg1−xZnx)2NbO6 (0≤x≤0.1) ceramics were prepared by the solid-state reaction method. The phase structure, microstructure and microwave dielectric properties of Li3(Mg1−xZnx)2NbO6 ceramics were analyzed via an X-ray diffraction, a scanning electron microscope as well as a network analyzer. All samples sintered at 1080-1240 °C for 4 h remained a single orthorhombic structure, which could be indexed according to the Li3Mg2NbO6 phase (JCPDS-PDF #86-0346). The microwave dielectric properties of Li3(Mg1−xZnx)2NbO6 ceramics exhibited significant dependence on the sintering condition, microstructure and composition. Excellent microwave dielectric properties (εr~17.2, Q×f~142,331 GHz, τf~−23.2 ppm/°C) were obtained in the x=0.08 sample sintered at 1120 °C for 4 h in air. In addition, the 0.17Li2O-0.83V2O5 composition was added as a sintering aid to lower the sintering temperature. The 0.5 wt% 0.17Li2O-0.83V2O5 added Li3(Mg0.92Zn0.08)2NbO6 ceramic showed fairly good microwave dielectric properties of εr~14, Q×f~83,395 GHz, τf~−37.2 ppm/°C when sintered at 925 °C for 2 h. Furthermore, there was no chemical reaction between Ag electrode and the sintering aid added sample, which further demonstrates that the Li3(Mg0.92Zn0.08)2NbO6 ceramic modified with 0.17Li2O-0.83V2O5 would be a promising candidate material for low-temperature cofired ceramic (LTCC) applications.
    Ceramics International 12/2014; 40(10):15677-15684. DOI:10.1016/j.ceramint.2014.07.090 · 2.61 Impact Factor
  • Chen Zhang · Ruzhong Zuo · Jian Zhang · Yang Wang ·
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    ABSTRACT: The crystal structure, microstructure, and microwave dielectric properties of forsterite-based (Mg1–xNix)2SiO4 (x = 0.02–0.20) ceramics were systematically investigated. All samples present a single forsterite phase of an orthorhombic structure with a space group Pbnm except for a little MgSiO3 secondary phase as x > 0.08. Lattice parameters in all axes decrease linearly with increasing Ni content due to the smaller ionic radius of Ni2+ compared to Mg2+. The substitution of an appropriate amount of Ni2+ could greatly improve the sintering behavior and produce a uniform and closely packed microstructure of the Mg2SiO4 ceramics such that a superior Q × f value (152 300 GHz) can be achieved as x = 0.05. The τf value was found to increase with increasing A-site ionic bond valences. In addition, various additives were used as sintering aids to lower the sintering temperature from 1500°C to the middle sintering temperature range. Excellent microwave dielectric properties of εr~6.9, Q × f~99800 GHz and τf~−50 ppm/°C can be obtained for 12 wt% Li2CO3-V2O5-doped (Mg0.95Ni0.05)2SiO4 ceramics sintered at 1150°C for 4 h.
    Journal of the American Ceramic Society 11/2014; 98(3). DOI:10.1111/jace.13347 · 2.61 Impact Factor
  • Feng Li · Ruzhong Zuo · Donggeng Zheng · Longtu Li ·
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    ABSTRACT: New lead-free perovskite solid solution ceramics of (1 − x)(Bi1/2Na1/2)TiO3–xBa(Ni1/2Nb1/2)O3[(1−x)BNT–xBNN,x = 0.02–0.06) were prepared and their dielectric, ferroelectric, piezoelectric, and electromechanical properties were investigated as a function of the BNN content. The X-ray diffraction results indicated that the addition of BNN has induced a morphotropic phase transformation from rhombohedral to pseudocubic symmetry approximately at x = 0.045, accompanying an evolution of dielectric relaxor behavior as characterized by enhanced dielectric diffuseness and frequency dispersion. In the proximity of the ferroelectric rhombohedral and pseudocubic phase coexistence zone, the x = 0.045 ceramics exhibited optimal piezoelectric and electromechanical coupling properties of d33~121 pC/N and kp~0.27 owing to decreased energy barriers for polarization switching. However, further addition of BNN could cause a decrease in freezing temperatures of polar nanoregions till the coexistence of nonergodic and ergodic relaxor phases occurred near room temperature, especially for the x = 0.05 sample which has negligible negative strains and thus show the maximum electrostrain of 0.3% under an external electric field of 7 kV/mm, but almost vanished piezoelectric properties. This was attributed to the fact that the induced long-range ferroelectric order could reversibly switch back to its original ergodic state upon removal of external electric fields.
    Journal of the American Ceramic Society 11/2014; 98(3). DOI:10.1111/jace.13363 · 2.61 Impact Factor
  • Source
    Wanli Zhao · Ruzhong Zuo · Jian Fu · Min Shi ·
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    ABSTRACT: A composition-induced pseudocubic–tetragonal structural transition was found to be accompanied by a relaxor phase transformation in xBi(Mg0.5Ti0.5)O3–(0.75 − x)PbTiO3–0.25(Bi0.5Na0.5)TiO3 ternary solid solutions. Dielectric and ferroelectric measurements suggest the coexistence of ergodic and nonergodic relaxor phases within a single pseudocubic phase zone for samples with 0.50 < x < 0.51 where large electromechanical strains of up to 0.43% (Smax/Emax = 621 pm/V) can be generated. The mechanism was mainly ascribed to the accumulated effects of field-modulated continuous and reversible transformations from a pseudocubic ergodic phase to a rhombohedral short-range ordered phase (but not nonergodic polar phase), and finally to a long-range ordered ferroelectric tetragonal phase. These procedures were found to be strongly dependent on the applied field magnitudes. These findings were reasonably approved by a couple of measurements such as dielectric–temperature–frequency spectrum, ferroelectric polarization/strain hysteresis loops, polarization current density curves and particularly ex situ Raman spectrum and in situ high-resolution synchrotron X-ray diffraction.
    Journal of the European Ceramic Society 09/2014; 34(10):2299–2309. DOI:10.1016/j.jeurceramsoc.2014.01.040 · 2.95 Impact Factor
  • Shengbo Lu · Zhengkui Xu · Ruzhong Zuo ·
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    ABSTRACT: The effect of domain structures on the piezoelectric properties of three typical lead-free piezoelectric ceramics, (1-x)Bi0.5Na0.5TiO3-xBa-TiO3 (Na0.52K0.48-x)(Nb0.95-xTa0.05)O-3-xLiSbO(3) and 0.5Ba(Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3)TiO3, have been studied by transmission electron microscopy. By adding BaTiO3 in single phase Bi0.5Na0.5TiO3, domain structure changed from irregular domains into submicron lamellar domains and polar nano-regions. While in the later two system, regular submicron domains with nanodomains inside formed, which is an important feature of these two systems. It is suggested that the changes in domain structures in these systems have a dominant effect in the enhancement of the piezoelectric properties, comparing with single phase Bi0.5Na0.5TiO3, Na0.5K0.5NbO3 and BaTiO3.
    Ceramics International 09/2014; 40(8):13565-13571. DOI:10.1016/j.ceramint.2014.05.070 · 2.61 Impact Factor
  • Liangping Yu · Shishun Qi · Zhaosheng Ma · Ruzhong Zuo ·
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    ABSTRACT: This paper reports the experimental determination of the uniaxial viscosity for ceramic tapes made of three commercially available low-temperature cofired ceramic (LTCC), DuPont 951 (glass-ceramic), Ferro A6M (glass) and Yinfeng 8.5 (glass) by utilizing a novel vertical sintering in an optical dilatometer. The green tapes were vertically sintered at different isothermal temperatures ranging from 760 °C to 820 °C under their own weights. The densification behavior was systematically investigated through the measured sintering strains and the uniaxial viscosity was determined as a function of relative density based on a theoretical equation developed for ceramic tapes. The calculated uniaxial viscosities were compared with a previously reported model and good agreements were achieved. The activation energy for the uniaxial viscosity was found to be independent of the relative density and showed an average value of 290±47 kJ/mol for the DuPont tapes but was not accessible currently for the other glass-based LTCC tapes.
    Ceramics International 08/2014; 40(7):9367-9375. DOI:10.1016/j.ceramint.2014.02.004 · 2.61 Impact Factor

Publication Stats

2k Citations
353.90 Total Impact Points


  • 2007-2015
    • Hefei University of Technology
      • School of Materials Science and Engineering
      Luchow, Anhui Sheng, China
  • 2003-2008
    • Technical University Darmstadt
      • Research Area of Materials Science
      Darmstadt, Hesse, Germany
  • 2000
    • Tsinghua University
      • State Key Laboratory of New Ceramics and Fine Processing
      Peping, Beijing, China