The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Miloljub D. Lukovic - One of the best experts on this subject based on the ideXlab platform.
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Analysis and optimization of a thermal sensor system for measuring water flow
Sensors and Actuators A-physical, 2013Co-Authors: Obrad S. Aleksic, Maria Vesna Nikolić, Miloljub D. Lukovic, S.o. Aleksic, Pantelija M. NikolicAbstract:Abstract A simple thermal sensor system was designed for measuring water flow in the water mains using the heat loss principle with a NTC thick film segmented thermistor as a self-heating sensor. Thick film segmented Thermistors were screen printed on alumina substrate. NTC thermistor paste was formed of very fine Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 powder obtained by a combined mechanical activation/thermal treatment process, an organic vehicle and glass frit. The thermal sensor system was analyzed in the static and dynamic regime. A range constant voltage power supply was defined in the range 9–19 V for input water temperatures of 30–2 °C, maintaining a supply voltage in steps of 2 V for a change in 5 °C of input water temperature. This enables optimal operating power, i.e. heat generation on the self-heating thermistor. Measured calibration curves for different input water temperatures and input water flow rates were modeled, enabling interpolation of additional calculated curves to cover a wide range of input water temperatures.
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preparation and characterization of cu and zn modified nickel manganite ntc powders and thick film Thermistors
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2013Co-Authors: O S Aleksic, Miloljub D. Lukovic, B.m. Radojcic, N. Nikolic, Zorka Z. Djuric, M V Nikolic, Milan Radovanovic, Miodrag Mitric, Pantelija M. NikolicAbstract:Abstract A simple ball milling/thermal treatment procedure was applied to obtain fine thermistor powders. Three different powder compositions were analyzed–Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 , Cu 0.25 Ni 0.5 Zn 1.0 Mn 1.25 O 4 and Cu 0.4 Ni 0.5 Mn 2.1 O 4 . XRD analysis showed that all three powder compositions had a cubic spinel structure. Correlation between the sintering temperature, structure and resulting electrical properties was analyzed on bulk samples. Thick film pastes were composed and segmented thick film Thermistors were screen printed on alumina, dried and fired. SEM analysis revealed a typical dendrite structure with small grains and a developed surface area. Thick film sheet resistance was measured on a test matrix and the resistance decreased with increasing Cu content. The temperature dependence of sample resistance was measured in a climatic chamber enabling calculation of the material constant and activation energy. Aging of the obtained segmented Thermistors was analyzed and the resistivity drift was 0.23% for the Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 NTC thick film thermistor confirming greater stability of Thermistors containing Zn and Cu that in combination with the determined good thermistor characteristics make them good candidates for temperature and heat loss sensor applications.
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Optimization and Application of NTC Thick Film Segmented Thermistors
Key Engineering Materials, 2013Co-Authors: Maria Vesna Nikolić, Miloljub D. Lukovic, Obrad S. Aleksic, B.m. Radojcic, N. Nikolic, Zorka Z. DjuricAbstract:NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite Thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented Thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented Thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation.
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micro flow sensor for water using ntc thick film segmented Thermistors
Microelectronics International, 2009Co-Authors: O S Aleksic, M V Nikolic, S M Savic, Latko Z Sibinoski, Miloljub D. LukovicAbstract:Purpose – The purpose of this paper is to apply negative thermal coefficient (NTC) thick film segmented Thermistors (TFSTs) in a micro‐flow sensor for water.Design/methodology/approach – A TFST is printed using NTC paste based on nickel manganite. The resistance of this thermistor is measured in a climatic chamber and the resulting curves are calibrated. A micro‐flow sensor is designed using a self‐heated segmented thermistor. The sensing principle is based on heat loss depending on the water flow intensity through the capillary. Water flow calibration is performed. The sensor sensitivity, inertia, and stability are analyzed.Findings – The micro‐flow sensor exhibits good stability, suitable sensitivity, and inertia for integral measurements of water flow.Practical implications – Advantages of a micro‐flow sensor using a TFST include low energy consumption, simple measuring procedure, and passive electronics.Originality/value – This paper describes initial work on a micro‐flow sensor for water using TFSTs.
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em simulator analysis of optimal performance thick film segmented Thermistors versus material characteristics selection
IEEE Transactions on Instrumentation and Measurement, 2008Co-Authors: V Maric, Miloljub D. Lukovic, Ljiljana Zivanov, O S Aleksic, Aleksandar MenicaninAbstract:In this paper, an alternative approach to the analysis of thick-film segmented negative temperature coefficient Thermistors based on the use of a commercial electromagnetic simulator tool is presented. The influence of the geometrical parameters and material characteristics of the used thermistor paste on the overall thermistor performance was analyzed and simulated. A physical model for the segmented Thermistors is given in brief, together with experimental data. The diffusion of electrode metal into the thermistor layer was analyzed, simulated, and estimated. Obtained simulation results were compared with experimental results, and the validity of the adopted approach was verified.
Changlai Yuan - One of the best experts on this subject based on the ideXlab platform.
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electrical properties of sr bi mn fe o thick film ntc Thermistors prepared by screen printing
Sensors and Actuators A-physical, 2011Co-Authors: Changlai Yuan, Xinyu Liu, Meifang Liang, Changrong Zhou, Hua WangAbstract:Abstract The Sr–Bi–Mn–Fe–O (Sr:Bi:Mn:Fe = 0.2: x :0.5:0.3; x = 0.6, 0.8, 1.0, 1.2) thick films with good NTCR characteristics were produced by screen-printing, using a paste with organic binders alone. X-ray diffraction patterns of the thick films showed two main phases of Sr 0.3 Bi 0.7 MnO 3− y and SrFeO 3− m with perovskite structure besides some amount of the bismuth iron oxides. It was found by SEM that the films with the different Bi content have superior morphology and to be dense. The room-temperature resistivity ( ρ 25 ), thermistor constant ( B 25/85 ), and activation energy ( E a ) of the Sr–Bi–Mn–Fe–O NTC thermistor films increased with the increase of Bi content. The values of ρ 25 , B 25/85 , and E a of the NTC Thermistors were in the range of 406–1960 Ω cm, 3141–3693 K, and 0.275–0.324 eV, respectively. For composition x = 0.8, a maximum reliability of +3% resistivity drift and duration time over 800 h at aging temperature 300 °C were observed at sintering temperature 785 °C.
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electrical properties of lead free thick film ntc Thermistors based on perovskite type bacoiixcoiii2xbi1 3xo3
Materials Letters, 2011Co-Authors: Changlai Yuan, Xinyu Liu, C R ZhouAbstract:Abstract Lead-free thick film negative temperature coefficient (NTC) Thermistors based on perovskite-type BaCo II x Co III 2 x Bi 1 − 3 x O 3 ( x ≤ 0.1) were prepared by mature screen-printing technology. The microstructures of the thick films sintered at 720 °C were examined by X-ray diffraction and scanning electron microscopy. The electrical properties were analyzed by measuring the resistance-temperature characteristics. For the BaBiO 3 thick films, the room-temperature resistivity is 0.22 MΩ cm, while the room-temperature resistivity is sharply decreased to about 3 Ω cm by replacing of Bi with a small amount of Co. For compositions 0.02 ≤ x ≤ 0.1, the values of room-temperature resistivity ( ρ 23 ), thermistor constant ( B 25/85 ) and activation energy are in the range of 1.995–2.975 Ω cm, 1140–1234 K and 0.102–0.111 eV, respectively.
Pantelija M. Nikolic - One of the best experts on this subject based on the ideXlab platform.
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Analysis and optimization of a thermal sensor system for measuring water flow
Sensors and Actuators A-physical, 2013Co-Authors: Obrad S. Aleksic, Maria Vesna Nikolić, Miloljub D. Lukovic, S.o. Aleksic, Pantelija M. NikolicAbstract:Abstract A simple thermal sensor system was designed for measuring water flow in the water mains using the heat loss principle with a NTC thick film segmented thermistor as a self-heating sensor. Thick film segmented Thermistors were screen printed on alumina substrate. NTC thermistor paste was formed of very fine Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 powder obtained by a combined mechanical activation/thermal treatment process, an organic vehicle and glass frit. The thermal sensor system was analyzed in the static and dynamic regime. A range constant voltage power supply was defined in the range 9–19 V for input water temperatures of 30–2 °C, maintaining a supply voltage in steps of 2 V for a change in 5 °C of input water temperature. This enables optimal operating power, i.e. heat generation on the self-heating thermistor. Measured calibration curves for different input water temperatures and input water flow rates were modeled, enabling interpolation of additional calculated curves to cover a wide range of input water temperatures.
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preparation and characterization of cu and zn modified nickel manganite ntc powders and thick film Thermistors
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2013Co-Authors: O S Aleksic, Miloljub D. Lukovic, B.m. Radojcic, N. Nikolic, Zorka Z. Djuric, M V Nikolic, Milan Radovanovic, Miodrag Mitric, Pantelija M. NikolicAbstract:Abstract A simple ball milling/thermal treatment procedure was applied to obtain fine thermistor powders. Three different powder compositions were analyzed–Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 , Cu 0.25 Ni 0.5 Zn 1.0 Mn 1.25 O 4 and Cu 0.4 Ni 0.5 Mn 2.1 O 4 . XRD analysis showed that all three powder compositions had a cubic spinel structure. Correlation between the sintering temperature, structure and resulting electrical properties was analyzed on bulk samples. Thick film pastes were composed and segmented thick film Thermistors were screen printed on alumina, dried and fired. SEM analysis revealed a typical dendrite structure with small grains and a developed surface area. Thick film sheet resistance was measured on a test matrix and the resistance decreased with increasing Cu content. The temperature dependence of sample resistance was measured in a climatic chamber enabling calculation of the material constant and activation energy. Aging of the obtained segmented Thermistors was analyzed and the resistivity drift was 0.23% for the Cu 0.2 Ni 0.5 Zn 1.0 Mn 1.3 O 4 NTC thick film thermistor confirming greater stability of Thermistors containing Zn and Cu that in combination with the determined good thermistor characteristics make them good candidates for temperature and heat loss sensor applications.
Dinesh Amalnerkar - One of the best experts on this subject based on the ideXlab platform.
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accelarated publication low temperature synthesis and characterization of ntc powder and its lead free thick film Thermistors
Microelectronic Engineering, 2010Co-Authors: Shweta Jagtap, Sunit Rane, Suresh W Gosavi, Dinesh AmalnerkarAbstract:A general and simple chemical approach has been proposed to prepare negative temperature coefficient (NTC) powder material using commercially available tetra hydrated acetates of Mn, Co, Ni and oxalic acid. The thermal decomposition of Mn-Co-Ni oxalate at 700^oC leads to formation of spinel phases with fine powder material. Lead free thick film thermistor pastes were formulated using the synthesized spinel powders. Planar thick film thermistor patterns of the formulated pastes were screen printed on alumina substrates. The microstructure and electrical properties of these thick film Thermistors were determined. Depending on the powder preparation, the prepared thick film NTC Thermistors showed room temperature resistance in the range of [email protected] The values of thermistor constant, @b"2"5"/"3"0"0 ranged from 4014 to 4223K.
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preparation characterization and electrical properties of spinel type environment friendly thick film ntc Thermistors
Journal of The European Ceramic Society, 2008Co-Authors: Shweta Jagtap, Sunit Rane, Suresh W Gosavi, Dinesh AmalnerkarAbstract:Abstract Environment friendly thick film NTC Thermistors based on spinel-type semiconducting electroceramics of different compositions Mn 1.85 Co 0.8 Ni 0.35 O 4 , and Mn 1.85 Co 0.8 Ni 0.35 O 4 + RuO 2 were fabricated on alumina substrate. The basic bulk ceramics and the fired thick films were characterized by thermo-gravimetric analysis, X-ray diffraction, and scanning electron microscopy with energy depressive X-ray analysis. Thick film samples showed compact and homogeneous microstructure. The electrical parameters of the planar thick film NTC Thermistors were determined. Depending on the ceramic composition, the prepared thick film NTC Thermistors showed room temperature resistance in the range of 6–168 MΩ. The values of thermistor constant, β 25/300 ranged from 3600 to 4900 K.
Xinyu Liu - One of the best experts on this subject based on the ideXlab platform.
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electrical properties of sr bi mn fe o thick film ntc Thermistors prepared by screen printing
Sensors and Actuators A-physical, 2011Co-Authors: Changlai Yuan, Xinyu Liu, Meifang Liang, Changrong Zhou, Hua WangAbstract:Abstract The Sr–Bi–Mn–Fe–O (Sr:Bi:Mn:Fe = 0.2: x :0.5:0.3; x = 0.6, 0.8, 1.0, 1.2) thick films with good NTCR characteristics were produced by screen-printing, using a paste with organic binders alone. X-ray diffraction patterns of the thick films showed two main phases of Sr 0.3 Bi 0.7 MnO 3− y and SrFeO 3− m with perovskite structure besides some amount of the bismuth iron oxides. It was found by SEM that the films with the different Bi content have superior morphology and to be dense. The room-temperature resistivity ( ρ 25 ), thermistor constant ( B 25/85 ), and activation energy ( E a ) of the Sr–Bi–Mn–Fe–O NTC thermistor films increased with the increase of Bi content. The values of ρ 25 , B 25/85 , and E a of the NTC Thermistors were in the range of 406–1960 Ω cm, 3141–3693 K, and 0.275–0.324 eV, respectively. For composition x = 0.8, a maximum reliability of +3% resistivity drift and duration time over 800 h at aging temperature 300 °C were observed at sintering temperature 785 °C.
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electrical properties of lead free thick film ntc Thermistors based on perovskite type bacoiixcoiii2xbi1 3xo3
Materials Letters, 2011Co-Authors: Changlai Yuan, Xinyu Liu, C R ZhouAbstract:Abstract Lead-free thick film negative temperature coefficient (NTC) Thermistors based on perovskite-type BaCo II x Co III 2 x Bi 1 − 3 x O 3 ( x ≤ 0.1) were prepared by mature screen-printing technology. The microstructures of the thick films sintered at 720 °C were examined by X-ray diffraction and scanning electron microscopy. The electrical properties were analyzed by measuring the resistance-temperature characteristics. For the BaBiO 3 thick films, the room-temperature resistivity is 0.22 MΩ cm, while the room-temperature resistivity is sharply decreased to about 3 Ω cm by replacing of Bi with a small amount of Co. For compositions 0.02 ≤ x ≤ 0.1, the values of room-temperature resistivity ( ρ 23 ), thermistor constant ( B 25/85 ) and activation energy are in the range of 1.995–2.975 Ω cm, 1140–1234 K and 0.102–0.111 eV, respectively.
