The Experts below are selected from a list of 10812 Experts worldwide ranked by ideXlab platform
Hiroshi Tamura - One of the best experts on this subject based on the ideXlab platform.
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role of donor and acceptor ions in the dielectric loss tangent of zr0 8sn0 2 tio4 dielectric Resonator Material
Journal of the American Ceramic Society, 1995Co-Authors: Nobuhiko Michiura, Tsutomu Tatekawa, Yukio Higuchi, Hiroshi TamuraAbstract:The role of donor and acceptor ions in the dielectric loss tangent of (Zr,Sn)TiO 4 was investigated at frequencies from 0.1 kHz to 9 GHz. When a specimen was doped with Fe 2 O 3 , the loss tangent increased drastically at microwave frequencies. This increase is explained by a large concentration of Fe- 3+ ions and oxygen vacancies in the grains. When the specimen was doped with Ta 2 O 5 and then annealed in a reducing atmosphere, electrical resistivity decreased and tan δ increased extremely at low frequencies but trivially at microwave frequencies. The high microwave δ value of Ta-doped specimens is explained by assuming the Ta ions in the crystal to be tetravalent. Dielectric loss is determined predominantly by space charge polarization at low frequencies and by the disordered charge distribution at microwave frequencies
Nobuhiko Michiura - One of the best experts on this subject based on the ideXlab platform.
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role of donor and acceptor ions in the dielectric loss tangent of zr0 8sn0 2 tio4 dielectric Resonator Material
Journal of the American Ceramic Society, 1995Co-Authors: Nobuhiko Michiura, Tsutomu Tatekawa, Yukio Higuchi, Hiroshi TamuraAbstract:The role of donor and acceptor ions in the dielectric loss tangent of (Zr,Sn)TiO 4 was investigated at frequencies from 0.1 kHz to 9 GHz. When a specimen was doped with Fe 2 O 3 , the loss tangent increased drastically at microwave frequencies. This increase is explained by a large concentration of Fe- 3+ ions and oxygen vacancies in the grains. When the specimen was doped with Ta 2 O 5 and then annealed in a reducing atmosphere, electrical resistivity decreased and tan δ increased extremely at low frequencies but trivially at microwave frequencies. The high microwave δ value of Ta-doped specimens is explained by assuming the Ta ions in the crystal to be tetravalent. Dielectric loss is determined predominantly by space charge polarization at low frequencies and by the disordered charge distribution at microwave frequencies
Yukio Higuchi - One of the best experts on this subject based on the ideXlab platform.
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role of donor and acceptor ions in the dielectric loss tangent of zr0 8sn0 2 tio4 dielectric Resonator Material
Journal of the American Ceramic Society, 1995Co-Authors: Nobuhiko Michiura, Tsutomu Tatekawa, Yukio Higuchi, Hiroshi TamuraAbstract:The role of donor and acceptor ions in the dielectric loss tangent of (Zr,Sn)TiO 4 was investigated at frequencies from 0.1 kHz to 9 GHz. When a specimen was doped with Fe 2 O 3 , the loss tangent increased drastically at microwave frequencies. This increase is explained by a large concentration of Fe- 3+ ions and oxygen vacancies in the grains. When the specimen was doped with Ta 2 O 5 and then annealed in a reducing atmosphere, electrical resistivity decreased and tan δ increased extremely at low frequencies but trivially at microwave frequencies. The high microwave δ value of Ta-doped specimens is explained by assuming the Ta ions in the crystal to be tetravalent. Dielectric loss is determined predominantly by space charge polarization at low frequencies and by the disordered charge distribution at microwave frequencies
Tsutomu Tatekawa - One of the best experts on this subject based on the ideXlab platform.
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role of donor and acceptor ions in the dielectric loss tangent of zr0 8sn0 2 tio4 dielectric Resonator Material
Journal of the American Ceramic Society, 1995Co-Authors: Nobuhiko Michiura, Tsutomu Tatekawa, Yukio Higuchi, Hiroshi TamuraAbstract:The role of donor and acceptor ions in the dielectric loss tangent of (Zr,Sn)TiO 4 was investigated at frequencies from 0.1 kHz to 9 GHz. When a specimen was doped with Fe 2 O 3 , the loss tangent increased drastically at microwave frequencies. This increase is explained by a large concentration of Fe- 3+ ions and oxygen vacancies in the grains. When the specimen was doped with Ta 2 O 5 and then annealed in a reducing atmosphere, electrical resistivity decreased and tan δ increased extremely at low frequencies but trivially at microwave frequencies. The high microwave δ value of Ta-doped specimens is explained by assuming the Ta ions in the crystal to be tetravalent. Dielectric loss is determined predominantly by space charge polarization at low frequencies and by the disordered charge distribution at microwave frequencies
Andre N Luiten - One of the best experts on this subject based on the ideXlab platform.
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nano kelvin thermometry and temperature control beyond the thermal noise limit
Physical Review Letters, 2014Co-Authors: Wenle Weng, James Anstie, T M Stace, Geoff Campbell, Fred N Baynes, Andre N LuitenAbstract:We demonstrate thermometry with a resolution of 80nK/Hz using an isotropic crystalline whispering-gallery mode Resonator based on a dichroic dual-mode technique. We simultaneously excite two modes that have a mode frequency ratio that is very close to two (±0.3ppm). The wavelength and temperature dependence of the refractive index means that the frequency difference between these modes is an ultrasensitive proxy of the Resonator temperature. This approach to temperature sensing automatically suppresses sensitivity to thermal expansion and vibrationally induced changes of the Resonator. We also demonstrate active suppression of temperature fluctuations in the Resonator by controlling the intensity of the driving laser. The residual temperature fluctuations are shown to be below the limits set by fundamental thermodynamic fluctuations of the Resonator Material.