The Experts below are selected from a list of 20583 Experts worldwide ranked by ideXlab platform

Enrico Traversa - One of the best experts on this subject based on the ideXlab platform.

  • sol gel processed tio2 based nano sized powders for use in thick film gas sensors for atmospheric pollutant monitoring
    Journal of Sol-Gel Science and Technology, 2001
    Co-Authors: Enrico Traversa, Maria Cristina Carotta, Maria Luisa Di Vona, Silvia Licoccia, M Sacerdoti, Luigi Crema, G Martinelli
    Abstract:

    Sol-gel routes were used to prepare pure and 5 at% and 10 at% Ta- or Nb-dope TiO2 nano-sized powders. The thermal decomposition behaviour of the precursors was studied using simultaneous thermogravimetric and differential thermal analysis (TG/DTA). X-ray diffraction (XRD) analysis showed that the powders heated to 400°C were crystalline in the anatase TiO2 structure. The pure TiO2 powder heated to 850°C showed the rutile structure. The addition of Ta and Nb inhibited the anatase-to-rutile phase transformation up to 950–1050°C. Ta was soluble in the titania lattice up to the concentration of 10 at%, while the solubility of Nb was 5 at%. Thick films were fabricated with these powders by screen printing technology and then fired for 1 h at different temperatures in the 650–1050°C range. Scanning electron microscopy (SEM) observations showed that the anatase-to-rutile phase transformation induces a grain growth of about one order of magnitude for pure TiO2. The addition of Ta and Nb is effective to keep the TiO2 grain size at a nanometric level even at 950°C, though grain growth was observed with increasing temperature. The gas-sensitive electrical response of the thick films were tested in laboratory, in environments with CO in dry and wet air. Conductance measurements showed a good gas response only for the nanostructured titania-based films. For field tests, the prototype sensors were placed beside a Conventional Station for atmospheric pollutant monitoring. The electrical response of the thick films was compared with the results of the analytical instruments. The same trend was observed for both systems, demonstrating the use of gas sensors for this aim.

  • Environmental monitoring field tests using screen-printed thick-film sensors based on semiconducting oxides
    Sensors and Actuators, B: Chemical, 2000
    Co-Authors: Enrico Traversa, Yoshihiko Sadaoka, Maria Cristina Carotta, Giuliano Martinelli
    Abstract:

    SnO2, TiO2, In2O3, LaFeO3, and SmFeO3 thick films have been prepared by screen-printing technology on alumina substrates with comb-type Au electrodes, starting either from commercial or laboratory-synthesized powders. An array of thick-film prototype sensors has been placed beside a Conventional Station for environmental monitoring. Field tests have been performed by measuring the change in conductivity of the thick films exposed to real atmosphere. Their electrical response has been compared with the results of the analytical instruments for environmental monitoring, approved by the international standards. The same trend was observed for both systems, with very promising results, when nanostructured oxides have been used for the preparation of the thick films. This allows us to consider as feasible the use of these sensors for cheap, innovative Stations for air quality control.

  • screen printed perovskite type thick films as gas sensors for environmental monitoring
    Sensors and Actuators B-chemical, 1999
    Co-Authors: G Martinelli, Yoshihiko Sadaoka, Maria Cristina Carotta, M Ferroni, Enrico Traversa
    Abstract:

    Abstract Thick films of LaFeO 3 and SmFeO 3 were fabricated by screen-printing technology on alumina substrates with comb-type Au electrodes. The perovskite-type oxide powders used for the preparation of the thick films have been prepared by the thermal decomposition at 700°C of hexacyanocomplexes, Ln[Fe(CN) 6 ] ·  n H 2 O. These powders are ultrafine, homogeneous, and free of intragranular pores. The films have been fired at different temperatures in the 750–1000°C range, in N 2 and air atmospheres. The gas-sensitive electrical response of the thick films have been tested in laboratory, in environments with different gases (CO and NO 2 ) in dry and wet air. For field tests, the prototype sensors have been placed beside a Conventional Station for environmental monitoring. The electrical response of the thick films has been compared with the results of the analytical instruments for environmental monitoring. The same trend was observed for both systems, with very promising results.

Maria Cristina Carotta - One of the best experts on this subject based on the ideXlab platform.

  • sol gel processed tio2 based nano sized powders for use in thick film gas sensors for atmospheric pollutant monitoring
    Journal of Sol-Gel Science and Technology, 2001
    Co-Authors: Enrico Traversa, Maria Cristina Carotta, Maria Luisa Di Vona, Silvia Licoccia, M Sacerdoti, Luigi Crema, G Martinelli
    Abstract:

    Sol-gel routes were used to prepare pure and 5 at% and 10 at% Ta- or Nb-dope TiO2 nano-sized powders. The thermal decomposition behaviour of the precursors was studied using simultaneous thermogravimetric and differential thermal analysis (TG/DTA). X-ray diffraction (XRD) analysis showed that the powders heated to 400°C were crystalline in the anatase TiO2 structure. The pure TiO2 powder heated to 850°C showed the rutile structure. The addition of Ta and Nb inhibited the anatase-to-rutile phase transformation up to 950–1050°C. Ta was soluble in the titania lattice up to the concentration of 10 at%, while the solubility of Nb was 5 at%. Thick films were fabricated with these powders by screen printing technology and then fired for 1 h at different temperatures in the 650–1050°C range. Scanning electron microscopy (SEM) observations showed that the anatase-to-rutile phase transformation induces a grain growth of about one order of magnitude for pure TiO2. The addition of Ta and Nb is effective to keep the TiO2 grain size at a nanometric level even at 950°C, though grain growth was observed with increasing temperature. The gas-sensitive electrical response of the thick films were tested in laboratory, in environments with CO in dry and wet air. Conductance measurements showed a good gas response only for the nanostructured titania-based films. For field tests, the prototype sensors were placed beside a Conventional Station for atmospheric pollutant monitoring. The electrical response of the thick films was compared with the results of the analytical instruments. The same trend was observed for both systems, demonstrating the use of gas sensors for this aim.

  • Environmental monitoring field tests using screen-printed thick-film sensors based on semiconducting oxides
    Sensors and Actuators, B: Chemical, 2000
    Co-Authors: Enrico Traversa, Yoshihiko Sadaoka, Maria Cristina Carotta, Giuliano Martinelli
    Abstract:

    SnO2, TiO2, In2O3, LaFeO3, and SmFeO3 thick films have been prepared by screen-printing technology on alumina substrates with comb-type Au electrodes, starting either from commercial or laboratory-synthesized powders. An array of thick-film prototype sensors has been placed beside a Conventional Station for environmental monitoring. Field tests have been performed by measuring the change in conductivity of the thick films exposed to real atmosphere. Their electrical response has been compared with the results of the analytical instruments for environmental monitoring, approved by the international standards. The same trend was observed for both systems, with very promising results, when nanostructured oxides have been used for the preparation of the thick films. This allows us to consider as feasible the use of these sensors for cheap, innovative Stations for air quality control.

  • screen printed perovskite type thick films as gas sensors for environmental monitoring
    Sensors and Actuators B-chemical, 1999
    Co-Authors: G Martinelli, Yoshihiko Sadaoka, Maria Cristina Carotta, M Ferroni, Enrico Traversa
    Abstract:

    Abstract Thick films of LaFeO 3 and SmFeO 3 were fabricated by screen-printing technology on alumina substrates with comb-type Au electrodes. The perovskite-type oxide powders used for the preparation of the thick films have been prepared by the thermal decomposition at 700°C of hexacyanocomplexes, Ln[Fe(CN) 6 ] ·  n H 2 O. These powders are ultrafine, homogeneous, and free of intragranular pores. The films have been fired at different temperatures in the 750–1000°C range, in N 2 and air atmospheres. The gas-sensitive electrical response of the thick films have been tested in laboratory, in environments with different gases (CO and NO 2 ) in dry and wet air. For field tests, the prototype sensors have been placed beside a Conventional Station for environmental monitoring. The electrical response of the thick films has been compared with the results of the analytical instruments for environmental monitoring. The same trend was observed for both systems, with very promising results.

Yoshihiko Sadaoka - One of the best experts on this subject based on the ideXlab platform.

  • Environmental monitoring field tests using screen-printed thick-film sensors based on semiconducting oxides
    Sensors and Actuators, B: Chemical, 2000
    Co-Authors: Enrico Traversa, Yoshihiko Sadaoka, Maria Cristina Carotta, Giuliano Martinelli
    Abstract:

    SnO2, TiO2, In2O3, LaFeO3, and SmFeO3 thick films have been prepared by screen-printing technology on alumina substrates with comb-type Au electrodes, starting either from commercial or laboratory-synthesized powders. An array of thick-film prototype sensors has been placed beside a Conventional Station for environmental monitoring. Field tests have been performed by measuring the change in conductivity of the thick films exposed to real atmosphere. Their electrical response has been compared with the results of the analytical instruments for environmental monitoring, approved by the international standards. The same trend was observed for both systems, with very promising results, when nanostructured oxides have been used for the preparation of the thick films. This allows us to consider as feasible the use of these sensors for cheap, innovative Stations for air quality control.

  • screen printed perovskite type thick films as gas sensors for environmental monitoring
    Sensors and Actuators B-chemical, 1999
    Co-Authors: G Martinelli, Yoshihiko Sadaoka, Maria Cristina Carotta, M Ferroni, Enrico Traversa
    Abstract:

    Abstract Thick films of LaFeO 3 and SmFeO 3 were fabricated by screen-printing technology on alumina substrates with comb-type Au electrodes. The perovskite-type oxide powders used for the preparation of the thick films have been prepared by the thermal decomposition at 700°C of hexacyanocomplexes, Ln[Fe(CN) 6 ] ·  n H 2 O. These powders are ultrafine, homogeneous, and free of intragranular pores. The films have been fired at different temperatures in the 750–1000°C range, in N 2 and air atmospheres. The gas-sensitive electrical response of the thick films have been tested in laboratory, in environments with different gases (CO and NO 2 ) in dry and wet air. For field tests, the prototype sensors have been placed beside a Conventional Station for environmental monitoring. The electrical response of the thick films has been compared with the results of the analytical instruments for environmental monitoring. The same trend was observed for both systems, with very promising results.

Giuliano Martinelli - One of the best experts on this subject based on the ideXlab platform.

  • Environmental monitoring field tests using screen-printed thick-film sensors based on semiconducting oxides
    Sensors and Actuators, B: Chemical, 2000
    Co-Authors: Enrico Traversa, Yoshihiko Sadaoka, Maria Cristina Carotta, Giuliano Martinelli
    Abstract:

    SnO2, TiO2, In2O3, LaFeO3, and SmFeO3 thick films have been prepared by screen-printing technology on alumina substrates with comb-type Au electrodes, starting either from commercial or laboratory-synthesized powders. An array of thick-film prototype sensors has been placed beside a Conventional Station for environmental monitoring. Field tests have been performed by measuring the change in conductivity of the thick films exposed to real atmosphere. Their electrical response has been compared with the results of the analytical instruments for environmental monitoring, approved by the international standards. The same trend was observed for both systems, with very promising results, when nanostructured oxides have been used for the preparation of the thick films. This allows us to consider as feasible the use of these sensors for cheap, innovative Stations for air quality control.

G Martinelli - One of the best experts on this subject based on the ideXlab platform.

  • sol gel processed tio2 based nano sized powders for use in thick film gas sensors for atmospheric pollutant monitoring
    Journal of Sol-Gel Science and Technology, 2001
    Co-Authors: Enrico Traversa, Maria Cristina Carotta, Maria Luisa Di Vona, Silvia Licoccia, M Sacerdoti, Luigi Crema, G Martinelli
    Abstract:

    Sol-gel routes were used to prepare pure and 5 at% and 10 at% Ta- or Nb-dope TiO2 nano-sized powders. The thermal decomposition behaviour of the precursors was studied using simultaneous thermogravimetric and differential thermal analysis (TG/DTA). X-ray diffraction (XRD) analysis showed that the powders heated to 400°C were crystalline in the anatase TiO2 structure. The pure TiO2 powder heated to 850°C showed the rutile structure. The addition of Ta and Nb inhibited the anatase-to-rutile phase transformation up to 950–1050°C. Ta was soluble in the titania lattice up to the concentration of 10 at%, while the solubility of Nb was 5 at%. Thick films were fabricated with these powders by screen printing technology and then fired for 1 h at different temperatures in the 650–1050°C range. Scanning electron microscopy (SEM) observations showed that the anatase-to-rutile phase transformation induces a grain growth of about one order of magnitude for pure TiO2. The addition of Ta and Nb is effective to keep the TiO2 grain size at a nanometric level even at 950°C, though grain growth was observed with increasing temperature. The gas-sensitive electrical response of the thick films were tested in laboratory, in environments with CO in dry and wet air. Conductance measurements showed a good gas response only for the nanostructured titania-based films. For field tests, the prototype sensors were placed beside a Conventional Station for atmospheric pollutant monitoring. The electrical response of the thick films was compared with the results of the analytical instruments. The same trend was observed for both systems, demonstrating the use of gas sensors for this aim.

  • screen printed perovskite type thick films as gas sensors for environmental monitoring
    Sensors and Actuators B-chemical, 1999
    Co-Authors: G Martinelli, Yoshihiko Sadaoka, Maria Cristina Carotta, M Ferroni, Enrico Traversa
    Abstract:

    Abstract Thick films of LaFeO 3 and SmFeO 3 were fabricated by screen-printing technology on alumina substrates with comb-type Au electrodes. The perovskite-type oxide powders used for the preparation of the thick films have been prepared by the thermal decomposition at 700°C of hexacyanocomplexes, Ln[Fe(CN) 6 ] ·  n H 2 O. These powders are ultrafine, homogeneous, and free of intragranular pores. The films have been fired at different temperatures in the 750–1000°C range, in N 2 and air atmospheres. The gas-sensitive electrical response of the thick films have been tested in laboratory, in environments with different gases (CO and NO 2 ) in dry and wet air. For field tests, the prototype sensors have been placed beside a Conventional Station for environmental monitoring. The electrical response of the thick films has been compared with the results of the analytical instruments for environmental monitoring. The same trend was observed for both systems, with very promising results.