Crystal structure, lattice vibration and microwave dielectric properties of 3CaO·2SiO2·xCaF2 (0 ≤ x ≤ 1.5) ceramics. Issue 10 (15th May 2022)

• Record Type: Journal Article
• Authors: Qin, Jincheng; Liu, Zhifu; Ma, Mingsheng; Li, Yongxiang
• Is Part Of: Ceramics international. Volume 48:Issue 10(2022)
• Page Start: 14371
• Page End: 14377
• Publication Date: 2022-05-15
• Subjects: 3CaO·2SiO2·xCaF2 ceramics -- Microwave dielectric properties -- Raman spectroscopy -- Quasi-optical resonator method; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.01.328
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The crystal structure, lattice vibration and microwave dielectric properties of 3CaO·2SiO2 · x CaF2 ceramics were investigated in this work. With the increasing of x value, the crystal structure of 3CaO·2SiO2 · x CaF2 ceramics transfers from rankinite (Ca3 Si2 O7 ) to cuspidine (Ca4 Si2 O7 F2 ). The increase of the vibration energy and shrinkage of [SiO4 ] tetrahedral unit hampers the ionic polarization and thus reduces relative permittivity ( ε r ). The enlarged FWHM of the Si–O stretching peak reflects a more drastic anharmonic lattice vibration, resulting in a lower quality factor (Q × f value). The Raman shift of O/F–Ca–O/F bending peak is positively correlated with the temperature coefficient of resonant frequency (τ f ). The microwave dielectric properties of εr and Q × f value (∼@11 GHz) ranging from 7.89 to 8.42, and 21805–46098 GHz, respectively. The stable complex permittivity ( ε r ∗ ) in the frequency range of 20–110 GHz indicates that the fluoride cuspidine ceramics could be a promising candidate for microwave device applications.