Effect of magnetic order on the conductivity in Co-Zn ferrites |
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Authors: | A Tawfik |
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Institution: | (1) Department of Physics, Faculty of Science, Tanta University, Tanta, Egypt |
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Abstract: | A series of samples in the system Co1–xZnxFe2O4 (x=0.3, 0.4, 0.6, 0.8 and 1) were prepared by the usual ceramic technique. The D. C. electrical resistivity and thermoelectric power were measured in the temperature range from room temperature up to about 600 K. Transition from the ferrimagnetic region to the paramagnetic region is accompanied by an increase in the activation energy by an amount E, which varies in the range 0.052–0.090 eV. The large values of E obtained may be due to the fairly strong B-B exchange interaction in Co-Zn ferrites.
Zusammenfassung Mittels üblicher Keramiktechniken wurden Proben des Systemes Co1–xZnxFe2O4 unterschiedlicher Zusammensetzung (x=0,3, 0,4, 0,6, 0,8, 1,0) dargestellt. Im Temperaturbereich Raumtemperatur-600 K wurde der elektrische Widerstand gegenüber Gleichstrom sowie die Thermospannung dieser Proben ermittelt. Der Übergang von der ferrimagnetischen zur paramagnetischen Region wird von einem Anwachsen der Aktivierungsenergie um den Betrag E=0,052–0,090 eV begleitet. Den so erhaltenen grossen E-Werten liegen wahrscheinlich die ziemlich starken B-B Austausch Wechselwirkungen in Co-Zn Ferriten zu Grunde.
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