Effects of structural characteristics on microwave dielectric properties of Li2Mg(Ti1−xMnx)3O8 ceramics

Zuo

2016

J. Am. Ceram. Soc.

Spinel‐structured (Zn1−x(Li2/3Ti1/3)x)2TiO4 (x = 0–1) microwave dielectric ceramics were manufactured via a conventional mixed‐oxide method. The X‐ray diffraction and Raman spectra revealed that a disordered face‐centered cubic phase was found in the composition range of x < 0.5, and an ordered primitive cubic spinel solid solution was achieved as x was beyond 0.5. Such a disorder–order transition near x = 0.5 was accompanied by the variation of composition‐induced cation occupancy. The Q × f value first kept increasing up to ~160 000 (GHz) in disordered ceramics, and then sharply decreased as an ordered structure appeared at x ≥ 0.5. An obvious decrease in τf value was also accompanied by the appearance of an ordered structure. The minimum τf value (~ −20 ppm/°C) was obtained in the x = 0.75 sample with the highest structural order degree. These results demonstrated that microwave dielectric properties of current spinel ceramics could be successfully modified by adjusting their structural order degree, which could be appropriately adopted for the design of spinel‐structured materials with favorable properties.

Section: Resultsmentioning

confidence: 99%

Effect of Ordering on the Microwave Dielectric Properties of Spinel‐Structured (Zn_1−x(Li_2/3Ti_1/3)_x)₂TiO₄ Ceramics

Zuo

2016

J. Am. Ceram. Soc.

“…Fig. 9 Zhang [23,24] had reported a strong relationship between bond energy E and τf , which the larger bond energy, the closer to zero the τf value. The E value of an individual bond μ could be calculated by Eq.…”

Section: Resultsmentioning

confidence: 94%

“…It relies on two formulas: the standard Lorentzian formula (Eq. (24)) and the Fresnel formula (Eq. ( 25)) [29,30].…”

Section: Resultsmentioning

confidence: 99%

“…Where bi U  and bi U  represent ionic energy part and covalent energy part, C f  is the bond ionicity of an individual bond , A Z  and B Z  are the valence states of cation and anion which constituted the  bond. Zhang [23,24] had reported a strong relationship between bond energy E and τf , which the larger bond energy, the closer to zero the τf value. The E value of an individual bond μ could be calculated by Eq.…”

Section: Figmentioning

confidence: 98%

See 1 more Smart Citation

Effects of (Mg1/3Sb2/3)4+ substitution on the structure and microwave dielectric properties of Ce2Zr3(Mg1/3Sb2/3)3-3(MoO4)9 ceramics

Wang

Liu

Sun

et al. 2021

Preprint

Ce 2 [Zr 1-x (Mg 1/3 Sb 2/3 ) x ] 3 (MoO 4 ) 9 (0.02≤x≤0.10) ceramics were prepared well through the traditional solid-state method. A single phase, belonging to the space group of R-3c, was detected by using X-ray diffraction at sintering temperatures ranging from 700 to 850 °C. The crystallization micro-structural of specimens was examined by applying Scanning electron microscopy. The structural refinement of these samples was investigated in detail by performing the Rietveld refinement method. The intrinsic properties were calculated and explored via far-infrared reflectivity spectroscopy. The correlations between the chemical bonds parameters and microwave dielectric properties were calculated and analyzed by P-V-L theory. Ce 2 [Zr 0.94 (Mg 1/3 Sb 2/3 ) 0.06 ] 3 (MoO 4 ) 9 ceramics with excellent dielectric properties: ε r = 10.37, Q×f = 71748 GHz and τ f = −13.6 ppm/°C sintered at 725 °C for 6 hours.

“…Where U µ bi and U µ bc represent ionic energy part and covalent energy part. Zhang [31,32] had reported a strong relationship between bond energy E and τf , which the larger bond energy, the closer to zero the τf value. The E value of an individual bond μ could be calculated by Eq.…”

Section: Figmentioning

confidence: 98%

Effects of (Mg1/3Sb2/3)4+ Substitution on the Structure and Microwave Dielectric Properties of Ce2Zr3x(Mg1/3Sb2/3)3-3x(MoO4)9 Ceramics

Sun

et al. 2020

Preprint

Ce2[Zr1-x(Mg1/3Sb2/3)x]3(MoO4)9 (0.02≤x≤0.10) ceramics were prepared well through the traditional solid-state method. A single phase, belonging to the space group of R-3c, was detected by using X-ray diffraction at sintering temperatures ranging from 700 to 850 °C. The crystallization micro-structural of specimens was examined by applying Scanning electron microscopy. The structural refinement of these samples was investigated in detail by performing the Rietveld refinement method. The intrinsic properties were calculated and explored via far-infrared reflectivity spectroscopy. The correlations between the chemical bonds parameters and microwave dielectric properties were calculated and analyzed by P-V-L theory. Ce2[Zr0.94(Mg1/3Sb2/3)0.06]3(MoO4)9 ceramics with excellent dielectric properties: εr = 10.37, Q×f = 71748 GHz and τf = −13.6 ppm/°C sintered at 725 °C for 6 hours.