Work

Enhanced microwave dielectric properties and low-temperature sintering of W6+-doped La2Mo2O9 ceramics

Year: 2025

Type: article

Abstract: Through a combination of systematic experimentation and theoretical modeling, La 2 Mo 2-x W x O 9 ceramics (x = 0.04–0.16) with a cubic phase (space group P2 1 3 ) were successfully prepared. The incorporation of W 6+ , owing to its larger ionic radius, resulted in the expansion of the unit cell. All samples attained high relative densities above 95% when sintered at 925 °C, and both bulk density and grain size were found to increase with higher W 6+ content. Optimal microwave dielectric properties were achieved at x = 0.08: a ε r of 18.5 was influenced by molecular polarizability and ionicity; the enhanced Q × f value (34,250 GHz) originated from a higher packing fraction and increased lattice energy of Mo/W–O bonds; and improved temperature stability ( τ f = -14.3 ppm/°C) was due to strengthened bond energy. Theoretical calculations based on the P–V–L model indicated that the dielectric properties are primarily governed by the Mo/W–O bonds, where ionicity dictates ε r , lattice energy affects Q × f , and bond energy controls τ f . A decrease in the full width at half maximum at 878 cm -1 in Raman spectra indicated reduced structural disorder, which is directly linked to the enhancement in Q × f . The optimized ceramic exhibits outstanding microwave performance and can be sintered at low temperatures, showing great potential for high-frequency applications in 5 G/6 G communications.

Source: Journal of Alloys and Compounds

DOI: 10.1016/j.jallcom.2025.184962

Authors: Zhenjun Qing, Xin Zhou, Haiyan Li, Yan Xue, Sen Peng

Institutions: Shaoyang University, Shenzhen Polytechnic University

Language: English

Topic: Microwave Dielectric Ceramics Synthesis

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,660