Crystal structure and microwave dielectric characteristics of Zr-substituted CoTiNb 2 O 8 ceramics

Zhang, Yun; Zhang, Yingchun; Xiang, Maoqiao

doi:10.1016/j.jeurceramsoc.2016.02.026

Cited by 65 publications

(22 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Raman spectroscopy is a powerful spectroscopic technique to probe the local structure of the atom and used to provide information about molecular vibrations and crystal structures. 13,29,30 Figure 6 shows the Raman spectra of the CaV 2 O 6 and (Ca 0.95 M 0.05 )V 2 O 6 (M=Zn 2+ ,Ba 2+ ) ceramics sintered at 650°C/4 h. As specified in Figure 5, the Raman spectra depicts nine main peaks in the wavenumber ranged from 100 to 1200 cm −1 , similar to the previous reports. According to the literature, 31 the bands with wavenumbers of 231, 106 and 160 cm −1 can be associated with the lattice vibrations.…”

Section: Raman Spectroscopysupporting

confidence: 81%

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

et al. 2019

View full text Add to dashboard Cite

In this study, the (Ca0.95M0.05)V2O6 (M = Zn, Ba) and the CaV2O6 ceramics were synthesized through a solid‐state reaction method, and the effects of Zn2+ and Ba2+ substitution on the structure, sintering temperature, densification, microstructure and microwave dielectric properties of CaV2O6 ceramic were analysed. The XRD patterns of the sintered samples indicated a single‐phase of CaV2O6 in all temperatures. Substitution of Zn2+ caused a lower sintering temperature and improved the densification of the CaV2O6 ceramic. While the dielectric properties of the (Ca0.95Ba0.05)V2O6 compound were not desirable, the (Ca0.95Zn0.05)V2O6 sample sintered at 650°C for 4 hours showed significant dielectric properties, with εr = 10.29, Q × f ~ 53 000 GHz (at 15.5 GHz) and τf = −72.37 ppm/°C. Moreover, the chemical compatibility of the CaV2O6 ceramic with Al electrode was examined.

show abstract

Section: Raman Spectroscopysupporting

confidence: 81%

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The other 3 modes (A 2g +2B 1u ) are neither Raman active nor infrared active. There are mainly three basic modes that attribute to CoTiNb 2 O 8 : lattice vibration for 122 cm -1 ; CoO 6 octahedra stretching deformation for 278 cm -1 and Nb-O symmetric vibration for 684 cm -1[22,23]. When the transition from rutile to columbite took place, the E g vibration mode caused by Ti-O stretching vibration disappeared at 455 cm -1 .…”

mentioning

confidence: 99%

Synthesis, characterization and dielectric properties of a novel temperature stable (1−x)CoTiNb2O8−xZnNb2O6 ceramic

Zhang

Xiang

2019

J Adv Ceram

Self Cite

View full text Add to dashboard Cite

(1−x)CoTiNb 2 O 8 −xZnNb 2 O 6 microwave dielectric ceramics were prepared via the conventional solid-state reaction route with the aim of reducing the τ f value and improving the thermal stability. The phase composition and the microstructure were investigated using X-ray diffraction, Raman spectra, and scanning electron microscopy. A set of phase transitions which were induced by composition had been confirmed via the sequence: rutile structure→coexistence of rutile and columbite phase→columbite phase. For (1−x)CoTiNb 2 O 8 −xZnNb 2 O 6 microwave dielectric ceramics, the addition of ZnNb 2 O 6 content (x = 0-1) led to the decrease of ε r from 62.98 to 23.94. As a result of the high Q × ƒ of ZnNb 2 O 6 ceramics, the increase of ZnNb 2 O 6 content also led to the lower sintering temperatures and the higher Q × ƒ values. The τ f value was reduced from +108.04 (x = 0) to-49.31 ppm/℃ (x = 1). Among them, high density 0.5CoTiNb 2 O 8 −0.5ZnNb 2 O 6 ceramics were obtained at 1175 ℃ with excellent microwave dielectric properties of ε r 39.2, Q × ƒ 40013 GHz, and τ f + 3.57 ppm/℃.

show abstract

“…The band at around 477 cm −1 may be attributed to Nb‐Nb stretching, while the band at around 771 cm −1 was assigned to Mg‐O bond vibrations . Notably, the band at 771 cm −1 was at first shifted to a higher wavenumber, and then, to a lower wavenumber, which was highly correlated to the variation in unit cell volume …”

Section: Resultsmentioning

confidence: 93%

“…41 Notably, the band at 771 cm −1 was at first shifted to a higher wavenumber, and then, to a lower wavenumber, which was highly correlated to the variation in unit cell volume. 42 Figure 4 shows the SEM micrographs of Li 3 Mg 2 Nb 1−x Ta x O 6 (x = 0, 0.01, 0.02, 0.03, and 0.04) samples. In the present work, the morphology, porosity and grain size were related to the compositions and dopant levels.…”

Section: Structural Analysismentioning

confidence: 99%

Crystal structure and enhanced microwave dielectric properties of Ta⁵⁺ substituted Li₃Mg₂NbO₆ ceramics

et al. 2019

View full text Add to dashboard Cite

Composition and structure play dominant roles in realizing the microwave dielectric properties that are necessary for the ever‐increasing demands of the Internet of Things and related communication technologies. In the present study, the substitution of Ta5+ in Li3Mg2Nb1−xTaxO6 ceramics and its effect on the structural characteristics and microwave dielectric performances is systematically studied. All the substituted compositions were determined to be pure phase orthorhombic Li3Mg2NbO6 structure of space group Fddd. Furthermore, a NbO6 octahedral distortion, Nb‐O bond valence, packing fraction and polarizability were calculated to explore the structure‐property‐performance paradigm in the context of microwave dielectric performance. Scanning electron microscopy revealed homogeneous microstructures, with the introduction of Ta5+ promoting grain growth. Raman spectra indicated that the variation of the band (blue shift and red shift) at 771 cm−1 was highly correlated with the variation in unit cell volume. The polarizability significantly impacted ɛr values. The Q × f values were strongly influenced by the packing fraction and grain size. The changes in the NbO6 octahedral distortion and Nb–O bond valence impacted the τf values. The Li3Mg2Nb0.98Ta0.02O6 composition displayed the most dramatic improvements in microwave dielectric properties: εr = 15.58, Q × f = 113 000 GHz and τf = −4.5 ppm/°C, providing a potential candidate for next generation microwave and millimeter‐wave applications.

show abstract

Crystal structure and microwave dielectric characteristics of Zr-substituted CoTiNb 2 O 8 ceramics

Cited by 65 publications

References 36 publications

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

Synthesis, characterization and dielectric properties of a novel temperature stable (1−x)CoTiNb2O8−xZnNb2O6 ceramic

Crystal structure and enhanced microwave dielectric properties of Ta⁵⁺ substituted Li₃Mg₂NbO₆ ceramics

Contact Info

Product

Resources

About

Crystal structure and microwave dielectric characteristics of Zr-substituted CoTiNb 2 O 8 ceramics

Cited by 65 publications

References 36 publications

Study on structure, microstructure and microwave dielectric characteristics of CaV2O6 and (Ca0.95M0.05)V2O6 (M=Zn, Ba) ceramics

Study on structure, microstructure and microwave dielectric characteristics of CaV2O6 and (Ca0.95M0.05)V2O6 (M=Zn, Ba) ceramics

Synthesis, characterization and dielectric properties of a novel temperature stable (1−x)CoTiNb2O8−xZnNb2O6 ceramic

Crystal structure and enhanced microwave dielectric properties of Ta5+ substituted Li3Mg2NbO6 ceramics

Contact Info

Product

Resources

About

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

Study on structure, microstructure and microwave dielectric characteristics of CaV₂O₆ and (Ca_0.95M_0.05)V₂O₆ (M=Zn, Ba) ceramics

Crystal structure and enhanced microwave dielectric properties of Ta⁵⁺ substituted Li₃Mg₂NbO₆ ceramics