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K. Park - One of the best experts on this subject based on the ideXlab platform.
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fabrication and electrical properties of mn ni co cu si oxides Negative Temperature Coefficient thermistors
Journal of the American Ceramic Society, 2005Co-Authors: K. ParkAbstract:The microstructure and electrical properties of Mn-Ni-Co-Cu-Si oxides Negative Temperature Coefficient (NTC) thermistors were studied. The as-sintered (Mn 1.62 Ni 0.72 Co 0.57-x Cu x Si 0.09 )O 4 (0≤X≤0.12) and (Mn 1.2 Ni 0.78 Co 0.87-x Cu 0.15 Si x )O 4 (0≤X≤ 0.15) ceramics showed the solid solutions of Mn-Ni-Co-Cu-Si oxides with a cubic spinel structure. The addition of SiO 2 led to an increase in the Temperature Coefficient of resistivity. This demonstrates that the SiO 2 addition is desirable for developing highly sensitive NTC thermistors. In addition, the resistivity and the Temperature Coefficient of resistivity for (Mn 1.62 Ni 0.72 Co 0.57-x Cu x Si 0.09 )O 4 and (Mn 1.2 Ni 0.78 Co 0.87-x Cu 0.15 Si x )O 4 NTC thermistors were controlled by changing the composition.
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Improvement in electrical stability by addition of SiO2 in (Mn1.2Ni0.78Co0.87−xCu0.15Six)O4 Negative Temperature Coefficient thermistors
Scripta Materialia, 2004Co-Authors: K. ParkAbstract:Abstract The electrical stability of (Mn1.2Ni0.78Co0.87−xCu0.15Six)O4 (0⩽x⩽0.15) Negative Temperature Coefficient (NTC) thermistors was studied by measuring the relative resistance change. The resistance change of the thermistors was significantly decreased by the addition of SiO2. It is proposed that the addition of SiO2 is desirable to achieve stable NTC thermistors.
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Influence of the composition on the electrical properties of (Mn2.1 - xNi0.9Six) O4 Negative Temperature Coefficient thermistors
Journal of Materials Science: Materials in Electronics, 2004Co-Authors: K. Park, S. J. YunAbstract:The influence of the composition on the electrical properties of (Mn2.1−x Ni0.9Si x )O4 (0≤x≤0.18) Negative Temperature Coefficient (NTC) thermistors was studied. Major phases present in the sintered bodies of (Mn2.1−x Ni0.9Si x )O4 ceramics were solid solutions of Mn–Ni–Si oxides with a cubic spinel structure. The relationship between log resistivity (log ρ) and the reciprocal of absolute Temperature (1/T) of the prepared NTC thermistors was linear, indicative of NTC characteristics. The resistivity, B 25/85 constant, and activation energy of the thermistors increased with increasing SiO2 content.
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Effect of SiO2 addition on the electrical stability of (Mn2.1−xNi0.9Six)O4 (0≦x≦0.18) Negative Temperature Coefficient thermistors
Materials Letters, 2004Co-Authors: K. Park, S. J. YunAbstract:Abstract The effect of SiO 2 addition on the electrical stability of (Mn 2.1− x Ni 0.9 Si x )O 4 (0≦ x ≦0.18) Negative Temperature Coefficient (NTC) thermistors was studied. The grain size decreased significantly with increasing SiO 2 content. The addition of SiO 2 led to a significant decrease in the resistance change of the thermistors, probably due to the grain refinement. It is therefore believed that the addition of SiO 2 is desirable to achieve stable NTC thermistors.
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microstructure and electrical properties of ni1 0mn2 xzrxo4 0 x 1 0 Negative Temperature Coefficient thermistors
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2003Co-Authors: K. ParkAbstract:Abstract The effect of the composition on the microstructure and electrical properties of Ni 1.0 Mn 2− x Zr x O 4 (0≤ x ≤1.0) Negative Temperature Coefficient (NTC) thermistors was studied. Major phases present in the sintered bodies of Ni 1.0 Mn 2− x Zr x O 4 were the solid solutions of Ni–Mn–Zr oxides with a cubic spinel structure and the ZrO 2 with a tetragonal structure. ZrO 2 was formed by the partial decomposition or incomplete formation of the Ni–Mn–Zr oxides during sintering. The ZrO 2 phase increased with an increase in the amount of added ZrO 2 . The relationship between log resistivity (log ρ ) and the reciprocal of absolute Temperature (1/ T ) of the prepared NTC thermistors was linear, indicative of NTC characteristics. The resistivity, B constant, and activation energy of the thermistors increased with an increase of ZrO 2 content.
Chan Park - One of the best experts on this subject based on the ideXlab platform.
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highly dense and nanograined nimn2o4 Negative Temperature Coefficient thermistor thick films fabricated by aerosol deposition
Journal of the American Ceramic Society, 2009Co-Authors: Jongjin Choi, Byungdong Hahn, Woonha Yoon, Dongsoo Park, Chan ParkAbstract:Highly dense, Negative Temperature Coefficient (NTC) thermistor thick films of NiMn2O4 were fabricated on glass substrate by aerosol deposition at room Temperature. The nanocrystalline films thus obtained showed superior NTC figure characteristics with a B constant of over 3900 K without heat treatment. With increasing annealing Temperature, the film resistivity was gradually decreased due to crystallization and grain growth, but the B constant was maintained over 3500 K.
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Highly Dense and Nanograined NiMn2O4 Negative Temperature Coefficient Thermistor Thick Films Fabricated by Aerosol‐Deposition
Journal of the American Ceramic Society, 2009Co-Authors: Jungho Ryu, Jongjin Choi, Byungdong Hahn, Woonha Yoon, Dongsoo Park, Kun-young Kim, Byung-kuk Lee, Chan ParkAbstract:Highly dense, Negative Temperature Coefficient (NTC) thermistor thick films of NiMn2O4 were fabricated on glass substrate by aerosol deposition at room Temperature. The nanocrystalline films thus obtained showed superior NTC figure characteristics with a B constant of over 3900 K without heat treatment. With increasing annealing Temperature, the film resistivity was gradually decreased due to crystallization and grain growth, but the B constant was maintained over 3500 K.
Silvania Lanfredi - One of the best experts on this subject based on the ideXlab platform.
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grain boundary electric characterization of zn7sb2o12 semiconducting ceramic a Negative Temperature Coefficient thermistor
Journal of Applied Physics, 2003Co-Authors: Marcos Augusto Lima Nobre, Silvania LanfrediAbstract:The electrical properties of the grain boundary region of electroceramic sensor Temperature based on inverse spinel Zn7Sb2O12 were investigated at high Temperature. The zinc antimoniate was synthesized by a chemical route based on the modified Pechini method. The electric properties of Zn7Sb2O12 were investigated by impedance spectroscopy in the frequency range from 5 Hz to 13 MHz and from 250 up to 600 °C. The grain boundary conductivity follows the Arrhenius law, with two linear branches of different slopes. These branches exhibit activation energies with very similar values; the low-Temperature (⩽350 °C) and high-Temperature (⩾400 °C) regions are equal to 1.15 and 1.16 eV, respectively. Dissimilar behavior is observed on the relaxation time (τ) curve as a function of Temperature, where a single slope is identified. The Negative Temperature Coefficient parameters and nature of the polarization phenomenon of the grain boundary are discussed.
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Negative Temperature Coefficient thermistor based on bi3zn2sb3o14 ceramic an oxide semiconductor at high Temperature
Applied Physics Letters, 2003Co-Authors: Marcos Augusto Lima Nobre, Silvania LanfrediAbstract:Bi1.5ZnSb1.5O7 dielectric ceramic with pyrochlore structure was investigated by impedance spectroscopy from 400 to 750 °C. Pyrochlore was synthesized by the polymeric precursor method, a chemical synthesis route derived from Pechini’s method. The grain or bulk resistance exhibits a sensor Temperature characteristic, being a thermistor with a Negative Temperature Coefficient (NTC). Only a single region was identified on the resistance curve investigated. The NTC thermistor characteristic parameter (β) is equal to 7140 °C, in the Temperature range investigated. The Temperature Coefficient of the resistance (α) was derived, being equal to −4.46×10−2 °C−1 at 400 °C. The conduction mechanism and relaxation are discussed.
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thermistor ceramic with Negative Temperature Coefficient based on zn7sb2o12 an inverse spinel type phase
Applied Physics Letters, 2002Co-Authors: Marcos Augusto Lima Nobre, Silvania LanfrediAbstract:The electric properties of the semiconductor ceramic Zn7Sb2O12 were investigated by impedance spectroscopy. The grain resistance exhibits a thermistor behavior with Negative Temperature Coefficient. Two regions on the resistance curve were identified. Each region shows a different thermistor characteristic parameter (β), which is equal to 3170 and 3845 °C, at measurement Temperatures up to 350 °C and above 450 °C, respectively. The Temperature Coefficient of the resistance (α) was derived being equal to −2.59×10−2 °C−1 and −1.89×10−2 °C−1, at 350 and 450 °C, respectively. The anomalous behavior of the resistance is further evidence of phase transition phenomenon.
Bo Zhang - One of the best experts on this subject based on the ideXlab platform.
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new Negative Temperature Coefficient ceramics in zr doped cacu3ti4o12 system
Journal of Alloys and Compounds, 2020Co-Authors: Xingyu Chen, Bo Zhang, Li Ni, Yang Zhou, Mingya Li, Aimin ChangAbstract:Abstract In this study, Negative Temperature Coefficient (NTC) ceramics based on CaCu3Ti4-xZrxO12(0 ≦ x ≦ 0.15) compositions have been successfully synthesized by traditional solid-state method. X-ray diffraction results show that the major phase of all samples is CaCu3Ti4O12 (CCTO) phase with body-centered cubic structure. The substitution of Zr4+ for Ti4+ inhibits the grain growth of CaCu3Ti4-xZrxO12 ceramics and greatly reduces the grain size. The results of X-ray photoelectron spectroscopy fully confirm the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions, which are one of the important reasons for conductivity of CaCu3Ti4-xZrxO12 samples. There is a good linear relationship between the natural logarithm of resistivity and reciprocal Temperature of all ceramic samples, which is consistent with NTC behavior. The obtained values of ρ150, B150/550 and Ea of the sintered samples are in the range of 1.62 × 105–3.39 × 105 Ω cm, 6378–6593 K and 0.550–0.568 eV, respectively.
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new Negative Temperature Coefficient ceramics in ca0 9y0 1moo4 cenbo4 system
Materials Letters, 2020Co-Authors: Bo Zhang, Zhilong Fu, Aimin ChangAbstract:Abstract The Ca0.9Y0.1CeNbMoO8 compounds are the solid solutions of Ca0.9Y0.1MoO4 and CeNbO4, and have a potential in the high Temperature thermistor application. A concept has been proposed to adjust the Negative Temperature Coefficient (NTC) properties of these thermistors by increasing the content of CeNbO4. The structure of as-sintered Ca0.9Y0.1MoO4–xCeNbO4 ceramics is a single Ca0.9Y0.1MoO4 phase at x
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New Negative Temperature Coefficient ceramics in Ca0.9Y0.1MoO4–CeNbO4 system
Materials Letters, 2020Co-Authors: Yafei Liu, Bo Zhang, Aimin ChangAbstract:Abstract The Ca0.9Y0.1CeNbMoO8 compounds are the solid solutions of Ca0.9Y0.1MoO4 and CeNbO4, and have a potential in the high Temperature thermistor application. A concept has been proposed to adjust the Negative Temperature Coefficient (NTC) properties of these thermistors by increasing the content of CeNbO4. The structure of as-sintered Ca0.9Y0.1MoO4–xCeNbO4 ceramics is a single Ca0.9Y0.1MoO4 phase at x
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New Negative Temperature Coefficient ceramics in Ca1−xYxCu3Ti3.9Zr0.1O12 system
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Chen Xingyu, Bo Zhang, Aimin ChangAbstract:The new Negative Temperature Coefficient (NTC) ceramics based on Ca1−xYxCu3Ti3.9Zr0.1O12 (x = 0, 0.01, 0.03, 0.05) compositions have been successfully synthesized by traditional solid-state method. The results of X-ray diffraction show that the major phase of all samples is CaCu3Ti4O12 (CCTO) with body-centered cubic structure. Scanning electron microscope images confirm that Y3+ doping can inhibit the growth of grains. X-ray photoelectron spectroscopy analysis fully demonstrates the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions in ceramic samples, and also proves that with the increase of Y3+ content, the concentration of Cu+ and Ti3+ ions increases, which is the main reason for the decrease of resistivity. The resistivity of all ceramic specimens decreases with the increase of Temperature, which is consistent with NTC behavior. The obtained values of ρ25, B200/500, and Ea of the sintered samples are in the range of 2.76 × 107–1.10 × 108 Ω cm, 6633–6755 K, and 0.572–0.582 eV, respectively.
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new Negative Temperature Coefficient ceramics in la doped cacu3ti4o12 system
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Bo Zhang, Aimin ChangAbstract:The Ca1-xLaxCu3Ti4O12 (0x0.3) ceramics have been successfully prepared by the traditional solid-state reaction method at 1090 degrees C for 10h. Effects of La3+ doping on the structure and Negative Temperature Coefficient electrical properties of Ca1-xLaxCu3Ti4O12 ceramics are investigated in detail. Scanning electron microscope images demonstrate that the grain size of ceramic samples decreases with the increasing La3+ content. X-ray photoelectron spectroscopy analysis further confirms the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions, which is one of the considerable contributors to the electrical conductivity of Ca1-xLaxCu3Ti4O12 ceramics. All the prepared ceramics show a linear relationship between the natural logarithm of the resistivity and the reciprocal of absolute Temperature, indicating NTC characteristics. The obtained values of (25), B-200/400 and Ea for the thermistors are in the range of 2.00x10(5)-5.22x10(7)cm(-1), 2644-4205K, 0.228-0.363eV, respectively.
Aimin Chang - One of the best experts on this subject based on the ideXlab platform.
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new Negative Temperature Coefficient ceramics in zr doped cacu3ti4o12 system
Journal of Alloys and Compounds, 2020Co-Authors: Xingyu Chen, Bo Zhang, Li Ni, Yang Zhou, Mingya Li, Aimin ChangAbstract:Abstract In this study, Negative Temperature Coefficient (NTC) ceramics based on CaCu3Ti4-xZrxO12(0 ≦ x ≦ 0.15) compositions have been successfully synthesized by traditional solid-state method. X-ray diffraction results show that the major phase of all samples is CaCu3Ti4O12 (CCTO) phase with body-centered cubic structure. The substitution of Zr4+ for Ti4+ inhibits the grain growth of CaCu3Ti4-xZrxO12 ceramics and greatly reduces the grain size. The results of X-ray photoelectron spectroscopy fully confirm the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions, which are one of the important reasons for conductivity of CaCu3Ti4-xZrxO12 samples. There is a good linear relationship between the natural logarithm of resistivity and reciprocal Temperature of all ceramic samples, which is consistent with NTC behavior. The obtained values of ρ150, B150/550 and Ea of the sintered samples are in the range of 1.62 × 105–3.39 × 105 Ω cm, 6378–6593 K and 0.550–0.568 eV, respectively.
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new Negative Temperature Coefficient ceramics in ca0 9y0 1moo4 cenbo4 system
Materials Letters, 2020Co-Authors: Bo Zhang, Zhilong Fu, Aimin ChangAbstract:Abstract The Ca0.9Y0.1CeNbMoO8 compounds are the solid solutions of Ca0.9Y0.1MoO4 and CeNbO4, and have a potential in the high Temperature thermistor application. A concept has been proposed to adjust the Negative Temperature Coefficient (NTC) properties of these thermistors by increasing the content of CeNbO4. The structure of as-sintered Ca0.9Y0.1MoO4–xCeNbO4 ceramics is a single Ca0.9Y0.1MoO4 phase at x
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New Negative Temperature Coefficient ceramics in Ca0.9Y0.1MoO4–CeNbO4 system
Materials Letters, 2020Co-Authors: Yafei Liu, Bo Zhang, Aimin ChangAbstract:Abstract The Ca0.9Y0.1CeNbMoO8 compounds are the solid solutions of Ca0.9Y0.1MoO4 and CeNbO4, and have a potential in the high Temperature thermistor application. A concept has been proposed to adjust the Negative Temperature Coefficient (NTC) properties of these thermistors by increasing the content of CeNbO4. The structure of as-sintered Ca0.9Y0.1MoO4–xCeNbO4 ceramics is a single Ca0.9Y0.1MoO4 phase at x
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New Negative Temperature Coefficient ceramics in Ca1−xYxCu3Ti3.9Zr0.1O12 system
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Chen Xingyu, Bo Zhang, Aimin ChangAbstract:The new Negative Temperature Coefficient (NTC) ceramics based on Ca1−xYxCu3Ti3.9Zr0.1O12 (x = 0, 0.01, 0.03, 0.05) compositions have been successfully synthesized by traditional solid-state method. The results of X-ray diffraction show that the major phase of all samples is CaCu3Ti4O12 (CCTO) with body-centered cubic structure. Scanning electron microscope images confirm that Y3+ doping can inhibit the growth of grains. X-ray photoelectron spectroscopy analysis fully demonstrates the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions in ceramic samples, and also proves that with the increase of Y3+ content, the concentration of Cu+ and Ti3+ ions increases, which is the main reason for the decrease of resistivity. The resistivity of all ceramic specimens decreases with the increase of Temperature, which is consistent with NTC behavior. The obtained values of ρ25, B200/500, and Ea of the sintered samples are in the range of 2.76 × 107–1.10 × 108 Ω cm, 6633–6755 K, and 0.572–0.582 eV, respectively.
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new Negative Temperature Coefficient ceramics in la doped cacu3ti4o12 system
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Bo Zhang, Aimin ChangAbstract:The Ca1-xLaxCu3Ti4O12 (0x0.3) ceramics have been successfully prepared by the traditional solid-state reaction method at 1090 degrees C for 10h. Effects of La3+ doping on the structure and Negative Temperature Coefficient electrical properties of Ca1-xLaxCu3Ti4O12 ceramics are investigated in detail. Scanning electron microscope images demonstrate that the grain size of ceramic samples decreases with the increasing La3+ content. X-ray photoelectron spectroscopy analysis further confirms the coexistence of Cu+/Cu2+ and Ti3+/Ti4+ ions, which is one of the considerable contributors to the electrical conductivity of Ca1-xLaxCu3Ti4O12 ceramics. All the prepared ceramics show a linear relationship between the natural logarithm of the resistivity and the reciprocal of absolute Temperature, indicating NTC characteristics. The obtained values of (25), B-200/400 and Ea for the thermistors are in the range of 2.00x10(5)-5.22x10(7)cm(-1), 2644-4205K, 0.228-0.363eV, respectively.
