Amelioration of sintering and multi-frequency dielectric properties of Mg3B2O6: A mechanism study of nickel substitution using DFT calculation

Rui Peng,Yuanming Lai,Huaiwu Zhang,Guoliang Yu,Xiaohui Wu,Hua Su,Yongcheng Lu,Yuanxun Li,Qin Zhang

doi:10.1007/s40145-021-0515-9

Abstract

With the support of density functional theory (DFT) calculation, the amelioration of sintering and dielectric properties of the Mg3B2O6 (MBO) ceramic was realized through the substitution of magnesium with nickel. The TE-mode cylindrical cavity method was used to measure the dielectric properties at different frequencies. The thermo-mechanical analysis and simultaneous thermal analysis were used to characterize the chemical and mechanical properties. The phase composition was determined through the X-ray diffraction (XRD) and Raman spectrum. The microstructure was investigated using the scanning electron microscopy (SEM). Magnesium substitution with nickel (4 mol%) could ionize the B-O bond of BO3, modify the vibration mode, improve the order degree, densify the microstructure, decrease the intrinsic densification temperature, and ameliorate the dielectric properties of the MBO ceramics. The maximum values were achieved for the ceramics with 4 mol% nickel and sintered at 1175 °C, that is, 97.2% for relative density, 72,600 GHz (10 GHz), 75,600 GHz (11.4 GHz), and 92,200 GHz (15 GHz) for Q × f, 7.1 (10 GHz), 7.01 (11.4 GHz), and 6.91 (15 GHz) for εr, and −56.3 ppm/°C for τf.

Highlights

Introduction−69 ppm/°C for τf, and 97% for relative density sintered at 1350 °C [7]. the oxide related to MBO is cheap, and a module fabricated using MBO could be equipped with a high added value
Materials with low dielectric constant and highJ Adv Ceram 2021, 10(5): 0–0−69 ppm/°C for τf, and 97% for relative density sintered at 1350 °C [7]
The recently reported dielectric properties at microwave frequency are mostly obtained at a specific frequency by the Hakki–Coleman method, which could not obtain the dielectric property of a material at different frequencies by only one sample [21,22]

Summary

Introduction

−69 ppm/°C for τf, and 97% for relative density sintered at 1350 °C [7]. the oxide related to MBO is cheap, and a module fabricated using MBO could be equipped with a high added value. The substitution of equivalence ions with different (ones with close) ionic radius and polarizability (e.g., Mg2+ with Co2+, Cu2+, and Ni2+) is an effective method to lower the intrinsic densification temperature, but the influence mechanism has not been discussed in detail [3,8,9,10,11,12,13]. The TE-mode cylindrical cavity method could obtain the frequency characteristics of a material without the making of different samples, and it avoids the risk of missing the resonance peak [23]. This method was used to measure the dielectric properties at different frequencies, and the solid-state reaction method was used to synthesise (Mg1−xNix)3B2O6 (MNBO) ceramics in this experiment (x varied from 0.00 to 0.07)

Experimental

Results and discussion

Conclusions