A High‐Q Microwave Dielectric Material Based on Mg₃B₂O₆

Abstract

The microwave dielectric properties and microstructure of Mg3B2O6 ceramics with the addition of 0–5 wt% Mg2B2O5 were investigated. Scanning electron microscopy of the Mg3B2O6 ceramics sintered at 1310°C revealed the presence of anisotropic, exaggeratedly grown grains with a crystallographic fault that extends along the direction of the anisotropy. The most pronounced, exaggerated grain growth was observed for Mg3B2O6 with 5 wt% of Mg2B2O5. The anisotropic grains were examined by electron backscatter diffraction. The analysis of the Kikuchi pattern showed that the crystallographic fault is a (011) twinning plane. The duration of annealing was found to have no significant effect on the dielectric permittivity, while the Q×f values increased two times with a prolongation of the annealing from 20 to 160 h. The highest Q×f value of 240 000 GHz was measured for Mg3B2O6 ceramics with 5 wt% of Mg2B2O5. These ceramics consisted of 10 times larger grains than the Mg3B2O6 ceramics without the added Mg2B2O5, which also showed high Q×f values of 200 000 GHz. The decrease of the amorphous phase during the annealing could be one of the reasons for this improvement of the Q×f values.

Synthesis and Microwave Dielectric Properties of Zn3B2O6 Ceramics for Substrate Application

“…Although the ceramic has low permittivity (~7) and high Qf value (>220 000 GHz), its sintering temperature is too high (>1200°C) to LTCC technology. 13,14 The structural properties of Zn 3 B 2 O 6 have been reported earlier. 15,16 It belongs to a monoclinic structure with space group C2/c.…”

“…reported the synthesis and dielectric characteristics of Mg 3 B 2 O 6 . Although the ceramic has low permittivity (~7) and high Qf value (>220 000 GHz), its sintering temperature is too high (>1200°C) to LTCC technology . The structural properties of Zn 3 B 2 O 6 have been reported earlier .…”

Effect of magnesium source on the fabrication of kotoite Mg3B2O6 ceramic

“…The Mg 3 B 2 O 6 is crystallized in orthorhombic unit cell with point group: 2/m 2/m 2/m, and the cell data as space group: Pnmn, a = 5.398(2), b = 8.416(2), c = 4.497(2) Å and Z = 2 . The single phase of Mg 3 B 2 O 6 , typical for ceramics with large grains (500‐1000 μm), have microwave dielectric properties with high Qxf values (˃200 000 GHz) …”

Synthesis, structural characterization, and photoluminescence properties of Eu3+‐doped Mg3‐xEux(BO3)2 phosphor

“…The Mg 3 (BO 3 ) 2 is an orthorhombic crystal with point group: 2/m 2/m 2/m, and the cell data are space group: Pnmn, a = 5.398(2), b = 8.416(2), c = 4.497(2) Å and Z = 2 . The single phase Mg 3 (BO 3 ) 2 , typical for ceramics with large grains (500‐1000 μm), have microwave dielectric properties with high Qxf values (˃200 000 GHz) . This article is emphasized on two points; one is usage of new method to synthesize kotoite form of Eu 3+ ‐doped magnesium borate, the other is investigation of the effect of concentration of Eu 3+ dopant on luminescence properties of magnesium borate.…”

“…12 The single phase Mg 3 (BO 3 ) 2 , typical for ceramics with large grains (500-1000 lm), have microwave dielectric properties with high Qxf values (˃200 000 GHz). 6,13 This article is emphasized on two points; one is usage of new method to synthesize kotoite form of Eu 3+ -doped magnesium borate, the other is investigation of the effect of concentration of Eu 3+ dopant on luminescence properties of magnesium borate. Moreover, the synthesis methods and the dopant composition also play a crucial role in luminescence properties of materials.…”