| Miniaturized ceramic capacitors with excellent dielectric properties and good temperature stability have become the development trend of currently electronic components.The purpose of this paper is to obtain a barium zirconium titanate?BZT?based ceramic capacitor material with high dielectric constant,low dielectric loss and low temperature change rate.This experiment uses Ba(Zr0.1Ti0.9)O3 ceramic as the matrix.x wt.%Ho2O3 doped?1-y?Ba(Zr0.1Ti0.9)O3-yBa(Zn1/3Nb2/3)O3?x=07,y=00.1?ceramics are prepared by solid state reaction.From the perspective of rare earth doping and system compounding,the effects of Ho2O3 doping amount,main crystal phase composition and sintering process on the microstructure and macroscopic properties of Ba(Zr0.1Ti0.9)O3 based ceramics were systematically studied.The phase composition and surface morphology of Ba(Zr0.1Ti0.9)O3 based ceramics were analyzed by X-ray diffraction?XRD?,scanning electron microscopy?SEM?and energy dispersive spectroscopy?EDS?.The results show that with the increase of Ho2O3 doping amount,Ba(Zr0.1Ti0.9)O3-based ceramics changed from perovskite-type single-phase solid solution to multiphase structure with Ho2Ti2O7 as the second phase,and the second phase Ho2Ti2O7 was formed.With the increase of Ba(Zn1/3Nb2/3)O3 molar amount,the lattice structure changed from pseudo-cubic phase to multi-phase coexistence;In the Ho2O3 doped Ba(Zr0.1Ti0.9)O3-Ba(Zn1/3Nb2/3)O3 ceramic system,the ceramics exhibit cubic phase perovskite structure.Dielectric temperature spectrum under multi-frequency,dielectric frequency spectrum and hysteresis loop of Ba(Zr0.1Ti0.9)O3 based ceramics were obtained by high-low temperature dielectric performance test system and ferroelectric test system,and the dispersion phase transition,frequency dispersion and ferroelectric relaxation behavior were further analyzed.The results show that with the increase of Ho2O3 doping amount or Ba(Zn1/3Nb2/3)O3 molar amount,the room temperature dielectric constant?rRT of Ba?Zr0.1Ti0.9?O3 based ceramics first increased and then decreased,and the dielectric loss at room temperature remained at about 0.01.Appropriately increasing the amount of Ho2O3doping or the molar amount of Ba(Zn1/3Nb2/3)O3 can enable Ba(Zr0.1Ti0.9)O3 based ceramics to realize transition from ordinary ferroelectrics to relaxor ferroelectrics;and the hysteresis loop of the ceramics transformed from"waist-shaped"ferroelectric to"linear"paraelectric;Increasing the sintering temperature or prolonging the holding time can finely adjust the curie temperature Tm of the Ba(Zr0.1Ti0.9)O3 based ceramics to near room temperature,which is favorable for the increase of the dielectric constant at room temperature.Under the optimal sintering process,it is beneficial to obtain a Ba(Zr0.1Ti0.9)O3 based ceramic capacitors with good temperature stability by appropriately increasing the doping amount of Ho2O3 and the molar amount of Ba(Zn1/3Nb2/3)O3.Finally,based on the best composition points in all ceramics,2 wt.%Ho2O3 doped0.97Ba(Zr0.1Ti0.9)O3-0.03Ba(Zn1/3Nb2/3)O3 ceramics having lower dielectric constant change rate???r/?r=-55.7+5%,-3085°C?,high dielectric constant at room temperature??r=6731.42?,low dielectric loss?tan?=0.009?,are expected to be used as the dielectrics for the environmentally friendly temperature-stabilized ceramic capacitors that meets the requirements of the Y5V standards. |
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