کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1811625 | 1025599 | 2011 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Structure, electric and dielectric studies of indium-substituted magnesium copper manganese ferrites Structure, electric and dielectric studies of indium-substituted magnesium copper manganese ferrites](/preview/png/1811625.png)
The structure, electric and dielectric properties of In-substituted Mg–Cu–Mn ferrites having the general formula of Mg0.9Cu0.1Mn0.1InxFe1.9−xO4 with 0.0≤x≤0.4 have been studied. X-ray diffraction (XRD) patterns of the samples indicated the formation of single-phase cubic spinel structure up to 0.2 and mixed phase (cubic and tetragonal phase) for samples x≥0.3. The relation of conductivity with temperature revealed a semiconductor to semimetal behavior as In+3 concentration increases. Variation in the universal exponent s with temperature indicates the presence of two hopping conduction mechanisms: the correlated barrier hopping (CHB) at low In+3 content x≤0.1 and small-polaron (SP) hopping at In+3 content x≥0.2. The variation in dielectric permittivity (ε′, ε″) with temperature at different frequencies shows a normal behavior for the studied compounds, while the variation in dielectric loss tangent with frequency at different temperatures shows abnormal behavior with more than relaxation peak. The conduction mechanism used in the present study has been discussed in the light of electron exchange between Fe3+ and Fe2+ ions and hole hopping between Mn2+ and Mn3+ ions at the octahedral B-sites.
Journal: Physica B: Condensed Matter - Volume 406, Issue 4, 15 February 2011, Pages 899–905