A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this stud...A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this study.The good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)ceramics.The pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature stability.Typically,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃.展开更多
A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,micros...A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,microstructures,and microwave dielectric properties were investigated.The results of x-ray diffraction(XRD)and scanning electron microscopy(SEM)showed that a single phase of MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with a spinel structure was obtained at x≤0.12,whereas the second phase of MgTi_(2)O_(5)appeared when x>0.12.The cell parameters were obtained by XRD refinement.As the x values increased,the unit cell volume kept expanding.This phenomenon could be attributed to the partial substitution of(Li_(1/3)Ti_(2/3))^(3+)for Al^(3+).Results showed that(Li_(1/3)Ti_(2/3))^(3+)doping into MgAl_(2)O_(4)spinel ceramics effectively reduced the sintering temperature and improved the quality factor(Q_f)values.Good microwave dielectric properties were achieved for a sample at x=0.20 sintering at 1500℃in air for 4 h:dielectric constantε_(r)=8.78,temperature coefficient of resonant frequencyτ_(f)=-85 ppm/℃,and Q_(f)=62300 GHz.The Q_(f)value of the x=0.20 sample was about 2 times higher than that of pure MgAl_(2)O_(4)ceramics(31600 GHz).Thus,MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with excellent microwave dielectric properties can be applied to 5G communications.展开更多
基金This study is supported by the National Key Research and Development Program of China(No.2022YFB2807405)the Qinchuangyuan Citing High-level Innovation and Entrepreneurship Talent Projects(No.QCYRCXM-2022-40)+2 种基金the National Natural Science Foundation of China(Nos.U2341263 and 62371366)Open project of Yunnan Precious Metals Laboratory Co.,Ltd(No.YPML-2023050246)Innovation Capability Support Program of Shaanxi,China(Nos.2023-CX-PT-30 and 2022TD-28).
文摘A glass frit containing Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)component was used to explore the low-temperature sintering behaviors and microwave dielectric characteristics of tri-rutile MgTa_(2)O_(6)ceramics in this study.The good low-firing effects are presented due to the high matching relevance between Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass and MgTa_(2)O_(6)ceramics.The pure tri-rutile MgTa_(2)O_(6)structure remains unchanged,and high sintering compactness can also be achieved at 1150℃.We found that the Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass not only greatly improves the low-temperature sintering characteristics of MgTa_(2)O_(6)ceramics but also maintains a high(quality factor(Q)×resonance frequency(f))value while still improving the temperature stability.Typically,great microwave dielectric characteristics when added with 2wt%Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)glass can be achieved at 1150℃:dielectric constant,ε_(r)=26.1;Q×f=34267 GHz;temperature coefficient of resonance frequency,τ_(f)=-8.7×10^(-6)/℃.
基金the Chengdu University of Technology(Grant No.KYQD201907728)。
文摘A series of nominal compositions MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)(x=0,0.04,0.08,0.12,0.16,and 0.20)ceramics were successfully prepared via the conventional solid-state reaction route.The phase compositions,microstructures,and microwave dielectric properties were investigated.The results of x-ray diffraction(XRD)and scanning electron microscopy(SEM)showed that a single phase of MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with a spinel structure was obtained at x≤0.12,whereas the second phase of MgTi_(2)O_(5)appeared when x>0.12.The cell parameters were obtained by XRD refinement.As the x values increased,the unit cell volume kept expanding.This phenomenon could be attributed to the partial substitution of(Li_(1/3)Ti_(2/3))^(3+)for Al^(3+).Results showed that(Li_(1/3)Ti_(2/3))^(3+)doping into MgAl_(2)O_(4)spinel ceramics effectively reduced the sintering temperature and improved the quality factor(Q_f)values.Good microwave dielectric properties were achieved for a sample at x=0.20 sintering at 1500℃in air for 4 h:dielectric constantε_(r)=8.78,temperature coefficient of resonant frequencyτ_(f)=-85 ppm/℃,and Q_(f)=62300 GHz.The Q_(f)value of the x=0.20 sample was about 2 times higher than that of pure MgAl_(2)O_(4)ceramics(31600 GHz).Thus,MgAl_(2-x)(Li_(1/3)Ti_(2/3))_(x)O_(4)ceramics with excellent microwave dielectric properties can be applied to 5G communications.
