Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound
A porous MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> bulk compound with varying SnO<sub>2</sub> content was obtained by sintering an appropriate mixture of magnesium oxide, hematite and tin oxide na...
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| Format: | Article |
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MDPI AG
2020-06-01
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| Series: | Chemosensors |
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| Online Access: | https://www.mdpi.com/2227-9040/8/2/39 |
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| author | Maria Vesna Nikolic Miloljub D. Lukovic |
| author_facet | Maria Vesna Nikolic Miloljub D. Lukovic |
| author_sort | Maria Vesna Nikolic |
| collection | DOAJ |
| description | A porous MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> bulk compound with varying SnO<sub>2</sub> content was obtained by sintering an appropriate mixture of magnesium oxide, hematite and tin oxide nanopowders at 1000 and 1100 °C. The obtained structure was confirmed by X-ray diffraction analysis. Scanning electron microscopy was used to analyze sample morphology, showing that the addition of SnO<sub>2</sub> resulted in an inhomogeneous microstructure with smaller grain size especially at 1000 °C. Significant grain growth of hematite grains was noted at 1100 °C. The influence of relative humidity in the range 30–90% was monitored at room temperature (25 °C) in the frequency range 42 Hz- 1 MHz. The highest reduction of impedance with humidity was noted at lower frequency. Addition of low amounts of SnO<sub>2</sub> and sintering at 1000 °C resulted in the highest sensitivity at 105 Hz of 0.391 MΩ/%RH in the RH30–90% range, while the compound with the highest amount of SnO<sub>2</sub> showed the largest decrease in impedance with increase in relative humidity ~26 times. All samples showed low hysteresis (below 2%). Complex impedance data was analyzed using equivalent circuits reflecting the dominant influence of the grain boundary in the lower relative humidity range (30–60%) and both grain boundary and grain components in the higher relative humidity range (60–90%). |
| first_indexed | 2024-03-10T19:08:32Z |
| format | Article |
| id | doaj.art-c2750b26055b45f08e2d5576e31dc3eb |
| institution | Directory Open Access Journal |
| issn | 2227-9040 |
| language | English |
| last_indexed | 2024-03-10T19:08:32Z |
| publishDate | 2020-06-01 |
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| spelling | doaj.art-c2750b26055b45f08e2d5576e31dc3eb2023-11-20T04:01:33ZengMDPI AGChemosensors2227-90402020-06-01823910.3390/chemosensors8020039Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> CompoundMaria Vesna Nikolic0Miloljub D. Lukovic1Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade, SerbiaInstitute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030 Belgrade, SerbiaA porous MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> bulk compound with varying SnO<sub>2</sub> content was obtained by sintering an appropriate mixture of magnesium oxide, hematite and tin oxide nanopowders at 1000 and 1100 °C. The obtained structure was confirmed by X-ray diffraction analysis. Scanning electron microscopy was used to analyze sample morphology, showing that the addition of SnO<sub>2</sub> resulted in an inhomogeneous microstructure with smaller grain size especially at 1000 °C. Significant grain growth of hematite grains was noted at 1100 °C. The influence of relative humidity in the range 30–90% was monitored at room temperature (25 °C) in the frequency range 42 Hz- 1 MHz. The highest reduction of impedance with humidity was noted at lower frequency. Addition of low amounts of SnO<sub>2</sub> and sintering at 1000 °C resulted in the highest sensitivity at 105 Hz of 0.391 MΩ/%RH in the RH30–90% range, while the compound with the highest amount of SnO<sub>2</sub> showed the largest decrease in impedance with increase in relative humidity ~26 times. All samples showed low hysteresis (below 2%). Complex impedance data was analyzed using equivalent circuits reflecting the dominant influence of the grain boundary in the lower relative humidity range (30–60%) and both grain boundary and grain components in the higher relative humidity range (60–90%).https://www.mdpi.com/2227-9040/8/2/39magnesium ferritehematitetin-oxidecomplex impedancehumidity sensing |
| spellingShingle | Maria Vesna Nikolic Miloljub D. Lukovic Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound Chemosensors magnesium ferrite hematite tin-oxide complex impedance humidity sensing |
| title | Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound |
| title_full | Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound |
| title_fullStr | Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound |
| title_full_unstemmed | Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound |
| title_short | Influence of SnO<sub>2</sub> Content on the Humidity Dependent Impedance of the MgFe<sub>2</sub>O<sub>4</sub>-Fe<sub>2</sub>O<sub>3</sub>-SnO<sub>2</sub> Compound |
| title_sort | influence of sno sub 2 sub content on the humidity dependent impedance of the mgfe sub 2 sub o sub 4 sub fe sub 2 sub o sub 3 sub sno sub 2 sub compound |
| topic | magnesium ferrite hematite tin-oxide complex impedance humidity sensing |
| url | https://www.mdpi.com/2227-9040/8/2/39 |
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