Conductimetric Response linearity in γ'-Bi2MoO6
Requisite conditions for electrical conductivity measurements in γ-Bi2MoO6 are reviewed, to optimize its application as a conductimetric chemical sensor. Constant voltage DC electrical resistivity and AC complex impedance measurements demonstrate that: (1) ohmic behavior is limited to a 50 mV maximu...
| Autores: | , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2006 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositório: | CONICET Digital (CONICET) |
| Idioma: | inglês |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/82116 |
| Acesso em linha: | http://hdl.handle.net/11336/82116 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Bismuth Molybdates Conductimetric chemical sensors Oxygen ionic conduction https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Resumo: | Requisite conditions for electrical conductivity measurements in γ-Bi2MoO6 are reviewed, to optimize its application as a conductimetric chemical sensor. Constant voltage DC electrical resistivity and AC complex impedance measurements demonstrate that: (1) ohmic behavior is limited to a 50 mV maximum voltage drop; (2) the influence of electrode polarization phenomena may be minimized by low frequency (10 Hz) AC measurements; (3) above 450ºC, electrical conduction is dominated by intracrystalline conduction; (4) below this operating temperature, the influence of surface and electronic conduction inhibit sensitivity and selectivity; (5) low frequency AC measurements with 50 mV rms excitation reflect changes in the partial pressure of oxygen. Keywords: Bismuth Molybdates; conductimetric chemical sensors; oxygen ionic conduction. Se analizan las condiciones requeridas para las medidas de conductividad eléctrica en la fase °’-Bi2MoO6, con el objeto de optimizar su aplicación como sensor químico conductimétrico. Medidas de resistividad eléctrica a potencial constante en c.c. y espectroscopia de impedancia en c.a., demuestran que: (1) el límite de comportamiento ohmico es 50 mV; (2) la influencia del fenómeno de polarización en los electrodos puede minimizarse mediante mediciones en c.a. a baja frecuencia (10 Hz); (3) por encima de 450ºC la conductividad eléctrica está dominada por la componente intracristalina; (4) por debajo de esta temperatura, la influencia de la conducción electrónica y superficial inhiben la sensibilidad y la selectividad; (5) medidas en c.a., a baja frecuencia y excitación de 50 mV rms, reflejan cambios en la presión parcial de oxígeno. |
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