Low dielectric loss and enhanced tunable properties of Mn-doped BST/MgO composites
Ba 0.6Sr 0.4Ti 1− x Mn x O 3 [BST(Mn), x = 0.0000, 0.0025, 0.0050, 0.0075, 0.0100 and 0.0125] powders were synthesized by solid-state reaction process, and then BST(Mn)/MgO ceramic composites (60 wt% MgO) were fabricated by conventional ceramic process. Mn was found distributed in the BST grains hom...
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Published in | Journal of alloys and compounds Vol. 490; no. 1; pp. 353 - 357 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier B.V
04.02.2010
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Ba
0.6Sr
0.4Ti
1−
x
Mn
x
O
3 [BST(Mn),
x
=
0.0000, 0.0025, 0.0050, 0.0075, 0.0100 and 0.0125] powders were synthesized by solid-state reaction process, and then BST(Mn)/MgO ceramic composites (60
wt% MgO) were fabricated by conventional ceramic process. Mn was found distributed in the BST grains homogeneously after sintering at 1420
°C for 4
h, neither grain-boundary segregation nor diffusion into the MgO grains could be found obviously. The dielectric nonlinearity of the materials was enhanced with the addition of Mn-dopant, and relatively high tunability, more than 27% (8
kV/mm DC field, 500
Hz), was obtained in BST(Mn)/MgO samples with
x
≤
0.0100. The dielectric loss at microwave frequency of the samples with Mn-dopant was significantly reduced, and a tremendously low dielectric loss was acquired for the sample with
x
=
0.0050, which is only 4.5
×
10
−3 (at 3.64
GHz). Both the low dielectric loss and enhanced tunable properties of the BST(Mn)/MgO composites are useful for tunable microwave applications. |
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ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2009.09.185 |