Guilin Academy of Air Force

Guilin, China

Guilin Academy of Air Force

Guilin, China
SEARCH FILTERS
Time filter
Source Type

Yuan C.L.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Zhou X.J.,Guilin University of Electronic Technology | Zhou C.R.,Guilin University of Electronic Technology | And 2 more authors.
Advances in Applied Ceramics | Year: 2013

The polycrystalline Ba1-xBixFe 0·9Sn0·1O3 (x50·1, 0·2, 0·3, 0·4 and 0·5) ceramics were prepared using a solid state reaction process, and the effect of Bi substitution on the microstructures and the electrical properties is investigated. The as sintered Ba1-xBixFe0·9Sn 0·1O3 ceramics showed the cubic perovskite structure with small amount of spinel BaFe2O4 and some residual Fe 2O3. As the Bi concentration increased, the ceramic grain size decreased and the pores or holes were reduced for the ceramics. The values of room temperature resistivity, thermistor constant and activation energy of the Ba1-xBixFe0·9Sn 0·1O3 thermistor ceramics, increasing with the rise of Bi content, were in the range of 1-1290 kΩ cm, 4469-7328 K and 0·385-0·632 eV respectively. The electrical properties of Ba 1-xBixFe0·9Sn0·1O 3 thermistor ceramics are mainly attributed to the contribution of grains, grain shells and grain boundaries by the impedance analysis. © 2013 Institute of Materials, Minerals and Mining.


Yuan C.,Guilin University of Electronic Technology | Yang T.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Zhou C.,Guilin University of Electronic Technology | And 2 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2014

The thick film NTC thermistor of compositions Sr0.6Bi 0.4Fe0.6Sn0.4O3 + BaCo II 0.02CoIII 0.04Bi 0.94O3, synthesized by solid state reaction, were prepared by screen-printing on alumina substrate. The microstructures, composition dependent, impedance characteristics, self-heating behaviours and thermistor properties were investigated. The relation between logarithm of resistivity and reciprocal of absolute temperature for the thick film thermistor was almost linear for all the compositions studied. The room-temperature resistivity, thermistor constant and activation energy of the films decreased with increasing BaCoII 0.02CoIII 0.04Bi 0.94O3 content and were in the range of 18.2-945.7 Ω cm, 1,753-2,649 K and 0.151-0.228 eV, respectively. The thick films showed the nearest-neighbor hopping or variable-range hopping model depended on the compositions. Impedance analysis indicated that the resistivity value of the thick films was mainly ascribed to the contribution of grains. At higher BaCoII 0.02CoIII 0.04Bi 0.94O3 content, a good self-heating effect of one thermistor film was observed. © 2014 Springer Science+Business Media New York.


Yuan C.,Guilin University of Electronic Technology | Yang Y.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Yang L.,Guilin University of Electronic Technology | And 2 more authors.
Bulletin of Materials Science | Year: 2014

A novel (1-x)Ba0.7Bi0.3Fe0.9Sn 0.1O3-xBaCoII 0.02CoIII 0.04Bi0.94O3 (0.2 = x = 0.9) negative temperature coefficient (NTC) thick film thermistors with high thermistor constant was prepared by screen printing. The values of room-temperature resistivity, thermistor constant and activation energy of the thick film thermistors, increasing with the addition of Ba0.7Bi 0.3Fe0.9Sn0.1O3, are in the range of 35.5 ω.cm-1.34 Mω.cm, 2067-6139 K and 0.177- 0.527 eV, respectively. This means that the electrical properties of the thick films are adjustable at a wide range, depending on the compositions. Impedance analysis shows that the magnitude of thick film bulk resistance is mainly attributed to the contribution of grain boundary. © Indian Academy of Sciences.


Yuan C.-L.,Guilin University of Electronic Technology | Liu X.-Y.,Guilin University of Electronic Technology | Liu X.-Y.,Central South University | Chen G.-H.,Guilin University of Electronic Technology | And 3 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2014

CuO and BaCo0.02 IICo0.04 III Bi0.94O3 co-doped Ba0.5Bi0.5Fe0.9 Sn0.1O3 thick films were fabricated by screen-printing technology. The phases, surface topologies and electrical properties of the thick films were characterized by X-ray diffraction, scanning electronic microscopy and AC impedance analyzer. The added CuO in thick films led to the decomposition of BaCo0.02 IICo0.04 III Bi0.94O3 compound and then the formation of non-perovskite bismuth barium oxides. A number of particle chains were observed in the thick-film thermistors and each particle in chains was composed of fine-grain Ba0.5Bi0.5Fe0.9 Sn0.1O3 and coarse-grain BaCo0.02 IICo0.04 III Bi0.94O3 with low melting. A lowest value of room-temperature resistivity was obtained for the thick-film composition containing 10% CuO. The resistivity drift of 2.3% with duration time about 300 h at aging temperature 150°C was observed for the film containing 4% CuO. The electrical properties of thick films were mainly attributed to the contribution of grain boundaries which showed the oxygen-vacancy conduction in low measured temperature range, and electron and oxygen-vacancy coupling conduction in high measured temperature region.


Yuan C.-L.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Zhou X.-J.,Guilin University of Electronic Technology | Yang Y.,Guilin University of Electronic Technology | And 2 more authors.
Wuji Cailiao Xuebao/Journal of Inorganic Materials | Year: 2014

Negative temperature coefficient thermistor ceramics based on Yn(Ba0.8Bi0.2)1-n Fe0.9Sn0.1O3 were fabricated by conventional solid-state reaction techniques. Phases, microstructures, resistance-temperature curves and impedance characteristics of thermistor ceramics were characterized by X-ray diffraction, scanning electron microscope, resistance-temperature tester and ac impedance analyzer, respectively. Yn(Ba0.8Bi0.2)1-n Fe0.9Sn0.1O3 thermistor ceramics with pseudo-cubic perovskite structure show average grain size of ~1.0 μm and the decreasing lattice parameter a with increase of Y content. Room-temperature resistivity, thermistor constant and activation energy of thermistor ceramics are in the range of 2.17-9.17 MΩ·cm, 6757-7171 K and 0.583-0.618 eV, respectively. When n=0.02 and 0.04, the ceramic resistance is mainly attributed to the contribution of grain boundaries, grains and grain shells. Among them, the resistance value of grain is the highest one. However, for the ceramics with n=0.06 and 0.08, the total resistance of thermistor ceramics is ascribed to the contribution of grain boundaries, domain walls and domains, and the domain regions show the larger resistance value than that of the other two elements. In the limited measured temperature range, all of grain boundaries, grain shells, grains, domain walls and domains show negative temperature coefficient thermistor behavior.


Cheng J.,Guilin University of Electronic Technology | Yuan C.-L.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Yang Y.,Guilin University of Electronic Technology | And 2 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2014

BaCo0.02 IICo0.04 III Bi0.94O3-BaSb0.04 Sn0.96O3 composite thick films were prepared by screen-printing technology. The microstructures and electrical properties of the thick films were characterized by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and a digital multimeter. The results indicate that the composite thermistor films are still composed of perovskite-type BaCo0.02 IICo0.04 III Bi0.94O3 and BaSb0.04Sn0.96O3 phases. The denser and more even film surface was observed as the BaCo0.02 IICo0.04 III Bi0.94O3 content increasing. The sintering temperatures, room-temperature resistivity(ρ25), thermistor constant (β25/85) and activation energy (Ea) of the composite films, decreased as the BaCo0.02 IICo0.04 III Bi0.94O3 content increasing, are in the range of 870-1000 °C, 2.5 kΩ·cm-2.35 M Ω·cm, 2764-4030 K and 0.238-0.348 eV, respectively.


Yuan C.-L.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Feng Q.,Guilin University of Electronic Technology | Yang Y.,Guilin University of Electronic Technology | And 2 more authors.
Rare Metals | Year: 2014

The BaFe0.9Sn0.1O3-BaCo 0.02 II Co 0.04 III Bi0.94O3 composite thick films were prepared by screen printing. X-ray diffraction (XRD) analysis confirms that the composite films are still composed of BaCo 0.02 II Co 0.04 III Bi0.94O3 and BaFe0.9Sn0.1O3 phases. For the prepared BaFe0.9Sn0.1O3-BaCo 0.02 II Co 0.04 III Bi0.94O3 composite thick films, a linear relationship between the logarithmic resistivity and the reciprocal of the absolute temperature is observed, indicating an excellent NTC thermistor characteristic. The values of resistivity at 25 °C, thermistor constant and activation energy, decreasing with BaCo 0.02 II Co 0.04 III Bi0.94O3 content increasing, are in the range of 8.9-92,990 Ω·cm, 1,126-3,777 K and 0.097-0.325 eV, respectively. Impedance analysis shows that at higher BaCo 0.02 II Co 0.04 III Bi0.94O3 content, the electrical properties of the composite films are mainly attributed to the contribution of grains and grain boundaries. With the gradual decrease of BaCo 0.02 II Co 0.04 III Bi0.94O3 content, the grain boundaries affect strongly the electrical properties of the composite films. © 2014 The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg.


Luo Y.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Li X.,Guilin University of Electronic Technology | Liu X.,Guilin University of Electronic Technology
Journal of Alloys and Compounds | Year: 2011

The microstructure and electrical properties of BaYxBi 1-xO3 thick film negative temperature coefficient thermistors, fabricated by screen printing, were investigated. The sintered thick films were the single-phase solid solutions of the BaYxBi 1-xO3 compounds with a monoclinic structure. The added Y2O3 led to a significant decrease in the grain size of the thermistors. The resistivity and coefficient of temperature sensitivity for the BaYxBi1-xO3 (0 ≤ x ≤ 0.15) thick film NTC thermistors decreased first with increasing x in the range of x < 0.04 and then increased with further increase in x. © 2010 Elsevier B.V. All rights reserved.


Li X.,Guilin University of Electronic Technology | Luo Y.,Guilin University of Electronic Technology | Luo Y.,Guilin Academy of Air Force | Liu X.,Guilin University of Electronic Technology
Journal of Alloys and Compounds | Year: 2011

The effect of the composition on the electrical properties of BaBi 1-xSbxO3 (0 ≤ x ≤ 0.5) negative temperature coefficient (NTC) thermistors was studied. Major phases present in the sintered bodies of BaBi1-xSbxO3 (0 < x < 0.5) ceramics were BaBi0.5Sb0.5O3 compounds with a rhombohedral structure and BaBiO3 compounds with a monoclinal structure. Most pores were located in the grains of BaBiO3 and BaBi0.5Sb0.5O3 ceramics. It was apparent that the ρ25 and B25/85 constant of the thermistors increased with increasing Sb content. © 2011 Elsevier B.V.

Loading Guilin Academy of Air Force collaborators
Loading Guilin Academy of Air Force collaborators