TY - JOUR
T1 - Phase evolution, phase transition, and microwave dielectric properties of scheelite structured xBi(Fe 1/3Mo 2/3)O 4-(1-x) BiVO 4 (0.0 ≤ x ≤ 1.0) low temperature firing ceramics
AU - Zhou, Di
AU - Pang, Li Xia
AU - Guo, Jing
AU - Qi, Ze Ming
AU - Shao, Tao
AU - Yao, Xi
AU - Randall, Clive A.
PY - 2012/10/28
Y1 - 2012/10/28
N2 - In the present work, the xBi(Fe 1/3Mo 2/3)O 4-(1-x)BiVO 4 (0.0 ≤ x ≤ 1.0) ceramics were prepared via the solid state reaction method. All the ceramics can be densified at low sintering temperatures around 820 °C. At room temperature, the BiVO 4 type scheelite monoclinic solid solution was formed in ceramic samples with a composition of x ≤ 0.10. When x lies between 0.1 and 0.7, a BiVO 4 scheelite tetragonal phase is formed at room temperature. In the range 0.7 ≤ x < 0.9, the ceramic samples were found to be composites consisting of BiVO 4 type tetragonal and Bi(Fe 1/3Mo 2/3)O 4 type monoclinic scheelite phases, and when x ≥ 0.9, the Bi(Fe 1/3Mo 2/3)O 4 type monoclinic scheelite solid solution was formed. In the BiVO 4 type monoclinic solid solution region, the phase transition to tetragonal phase was studied by in situ Raman and Far-Infrared spectroscopies and by thermal expansion analysis. All of these methods indicated that the phase transition temperature almost linearly decreased from 255 °C for pure BiVO 4 to about -9 °C for x = 0.1 sample. High performance microwave dielectric properties with a high permittivity of about 74.8, high Qf values above 11500 GHz, and a small temperature coefficient of resonant frequency within +20 ppm per °C in a wide temperature range of 20-140 °C can be obtained in the composite ceramic sample with 60 mol% x = 0.10 composition and 40 mol% x = 0.02 composition. The xBi(Fe 1/3Mo 2/3)O 4-(1-x)BiVO 4 (0.0 ≤ x ≤ 1.0) ceramics might provide useful candidate materials for microwave integrated capacitive devices, such as filters, antennas, etc.
AB - In the present work, the xBi(Fe 1/3Mo 2/3)O 4-(1-x)BiVO 4 (0.0 ≤ x ≤ 1.0) ceramics were prepared via the solid state reaction method. All the ceramics can be densified at low sintering temperatures around 820 °C. At room temperature, the BiVO 4 type scheelite monoclinic solid solution was formed in ceramic samples with a composition of x ≤ 0.10. When x lies between 0.1 and 0.7, a BiVO 4 scheelite tetragonal phase is formed at room temperature. In the range 0.7 ≤ x < 0.9, the ceramic samples were found to be composites consisting of BiVO 4 type tetragonal and Bi(Fe 1/3Mo 2/3)O 4 type monoclinic scheelite phases, and when x ≥ 0.9, the Bi(Fe 1/3Mo 2/3)O 4 type monoclinic scheelite solid solution was formed. In the BiVO 4 type monoclinic solid solution region, the phase transition to tetragonal phase was studied by in situ Raman and Far-Infrared spectroscopies and by thermal expansion analysis. All of these methods indicated that the phase transition temperature almost linearly decreased from 255 °C for pure BiVO 4 to about -9 °C for x = 0.1 sample. High performance microwave dielectric properties with a high permittivity of about 74.8, high Qf values above 11500 GHz, and a small temperature coefficient of resonant frequency within +20 ppm per °C in a wide temperature range of 20-140 °C can be obtained in the composite ceramic sample with 60 mol% x = 0.10 composition and 40 mol% x = 0.02 composition. The xBi(Fe 1/3Mo 2/3)O 4-(1-x)BiVO 4 (0.0 ≤ x ≤ 1.0) ceramics might provide useful candidate materials for microwave integrated capacitive devices, such as filters, antennas, etc.
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U2 - 10.1039/c2jm34603f
DO - 10.1039/c2jm34603f
M3 - Article
AN - SCOPUS:84867024716
SN - 0959-9428
VL - 22
SP - 21412
EP - 21419
JO - Journal of Materials Chemistry
JF - Journal of Materials Chemistry
IS - 40
ER -