Crystal Structures and Microwave Dielectric Properties of Novel MgCu2Nb2O8 Ceramics Prepared by Two-Step Sintering Technique

Sen Peng; Chen Li; Chao Tang; Sheng Liu; Shengxiang Huang; Leilei Qiu; Lianwen Deng

doi:10.3390/ma15228053

Crystal Structures and Microwave Dielectric Properties of Novel MgCu₂Nb₂O₈ Ceramics Prepared by Two-Step Sintering Technique

Materials (Basel). 2022 Nov 15;15(22):8053. doi: 10.3390/ma15228053.

Authors

Sen Peng^{1

2}, Chen Li¹, Chao Tang¹, Sheng Liu³, Shengxiang Huang¹, Leilei Qiu¹, Lianwen Deng¹

Affiliations

¹ School of Physics and Electronics, Central South University, Changsha 410083, China.
² Provincial Key Laboratory of Informational Service for Rural Area of Southwestern Hunan, Shaoyang University, Shaoyang 422000, China.
³ College of Mechanical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China.

Abstract

In this work, novel MgCu₂Nb₂O₈ (MCN) ceramics were synthesized by the two-step sintering (TSS) technique, and the phase composition, crystal structures, and microwave dielectric properties were comprehensively studied. X-ray diffraction (XRD) and Raman analysis demonstrated that MCN ceramics are multi-phase ceramics consisting of MgNb₂O₆ and CuO phases. X-ray photoelectron spectroscopy (XPS) was utilized to investigate the chemical composition and element valence of MgCu₂Nb₂O₈ ceramics. Scanning electron microscopy (SEM) analysis demonstrated dense microstructures in the MCN ceramics prepared at a sintering temperature of 925 °C. The microwave dielectric properties were largely affected by the lattice vibrational modes and densification level of the ceramics. The outstanding microwave dielectric properties of ε_r = 17.15, Q × f = 34.355 GHz, and τ_f = -22.5 ppm/°C were obtained for the MCN ceramics sintered at 925 °C, which are results that hold promise for low temperature co-fired ceramic (LTCC) applications.

Keywords: MgCu2Nb2O8 ceramics; annealing; crystal structure; microwave dielectric property.

Abstract

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