Crystal structure, Raman spectra and microwave dielectric properties of novel low-temperature cofired ceramic Li4GeO4

• Published in: Journal of alloys and compounds 2021-06, Vol.867, p.159059, Article 159059
• Main Authors: Yang, Zijian, Tang, Ying, Li, Jie, Fang, Weishuang, Ma, Jinyan, Yang, Aihong, Liu, Laijun, Fang, Liang
• Format: Article
• Language: English
• Subjects: Ceramics; Chemical compatibility; Crystal structure; Dielectric properties; Li4GeO4; Low temperature; LTCC; Microwave dielectric property; Olivine; Olivine structure; Raman spectra; Sintering
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.159059

A low-permittivity and low-loss ceramic, Li4GeO4, was fabricated via solid state reaction route. XRD showed that a single orthorhombic Li4GeO4 phase with olivine structure was prepared over the sintering temperature range of 660–740 °C. Dense ceramic sintered at 720 °C revealed excellent microwave properties, with εr ~6.99, Q × f ~47,813 GHz (at 15.5 GHz), and τf ~ − 159.2 ppm/°C. The microwave dielectric performances were analyzed with the intrinsic characteristics of crystal structure by ionic polarizability and Raman spectra. Additionally, the Li4GeO4 ceramic showed good chemical compatibility with Ag sintered at 720 °C. In the low-temperature cofired ceramic (LTCC) application, aforesaid results manifested that Li4GeO4 ceramic was considered as a potential candidate. •A low-permittivity and low-loss ceramic, Li4GeO4, was fabricated via solid state reaction route.•Dense ceramic sintered at 720 °C revealed excellent microwave properties, with εr ~ 6.99, Q × f ~ 47,813 GHz (at 15.2 GHz), and τf ~ –159.2 ppm/°C.•The microwave dielectric performances were analyzed with the intrinsic characteristics by ionic polarizability, packing fraction, and Raman spectra.