Dielectric behavior and ac electrical conductivity in samarium substituted Mg–Ni ferrites

Melagiriyappa, E.; Veena, M. G.; Somashekarappa, A.; Shankaramurthy, G J; Jayanna, H. S.

doi:10.1007/s12648-014-0498-2

Cited by 18 publications

(3 citation statements)

References 33 publications

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“…RE ions with relatively smaller radii have less tendency of diffusing towards grain boundaries, hence exhibit decrease in electrical resistivity. This behavior is observed for Mg1−xNixFe2−ySmyO4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.0, 0.05, 0.1) [88]. When Ni-Zn ferrite is doped with La, Yb, Dy and Ce ions, highest electrical resistivity is reported for La substituted ferrite [93].…”

Section: Electrical and Dielectric Propertiesmentioning

confidence: 71%

“…Hopping mechanism successfully explains conducting behavior in Cl0.5Zn0.5Fe1-xRxO4 (x=0.4 and x=1); (R=La, Nd, Sm, Gd and Dy) [87], Mg1−xNixFe2−ySmyO4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.0, 0.05, 0.1) [88], RE doped NixFe(3−x)O4 [89]. As discussed earlier, RE 3+ diffuse towards grain boundaries in ferrite, this causes formation of non conducting layers in grain boundaries.…”

Section: Electrical and Dielectric Propertiesmentioning

confidence: 84%

“…In analogy with these effects, DC electrical resistivity decreases for x=0.025 then increases up to x=0.1 for Gd 3+ doped nanocrystalline Co-ferrites CoGdxFe2-xO4 (x = 0.0 to 0.1). Dielectric constant (ɛ) and dielectric loss (tanδ) decrease with increase in frequency of Sm doped Mg-Ni-Zn ferrite and explain on decrease dielectric properties of Mg1−xNixFe2−ySmyO4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.0, 0.05, 0.1) and explained on the basis of Maxwell-Wagner's two layer model [88]. Dielectric properties of Ni0.5Zn0.5RyFe2−yO4; 0.0≤y≤0.9,( R=La, Yb, Dy and Ce) decreases with introduction of RE ions which is associated with Fe-Fe interaction and 3d-4f coupling [93].…”

Section: Electrical and Dielectric Propertiesmentioning

confidence: 99%

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Solubility limit, magnetic interaction and conduction mechanism in rare earth doped spinel ferrite

Singh¹,

Kumar²,

Srivastava³

et al. 2016

Appl. Sci. Lett.

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In present review we have focused various issues like solubility limit, magnetic interaction and conduction mechanism of rare earth doped ferrite. Cumulative effects of valence state, magnetic moments of rare earth ions, weakening/strengthening of exchange interaction and magnetic ordering in rare earth ion doped ferrite are responsible for magnetic behavior. It is proposed that characterization techniques based on synchrotron radiation like X-ray absorption spectroscopy and X-ray magnetic circular dichroism can open pathways to prove these assumptions.Keywords: Rare earth, ferrites, magnetic interaction, valence state 1.INTRODUCTIONSpinel ferrites are ferrimagnetic material which have numerous technological applications [1][2][3]. Moreover, nanoparticles of these ferrites are being utilized in high-density magnetic information storage, magnetic resonance imaging, drug delivery etc. [4][5][6]. These several applications are based on magnetic and electrical behavior of ferrites [1][2][3][4][5][6]. These properties depend on various factors like, ionic radii, nature of hybridization, presence of doped atom in host lattice apart from the particle size [7][8][9][10]. Thus, research is being carried out for doped ferrite systems in order to understand the altered behavior and to optimize them for different applications [11][12][13][14][15]. In recent years, rare earth (RE) doped ferrites become interesting due to their superiority for various applications over other doped ferrite systems [17][18][19][20][21][22]. These systems become radioactive and exhibit potentential for biomedical applications [19] along-with efficient tumor passive targeting [23]. Improved capability of dye removal [24], waste water treatment [25], degradation of organic pollutants through photocatalytic activity [26] are other important fields of utilization of these ferrites. These ferrites exhibit enhanced magneto optical kerr (MOKE) effect [20] and excellent microwave absorption properties [21,22]. Thus, these ferrites cover a wide range of applications chiefly based on their magnetic characteristics [17][18][19][20][21][22][23][24][25]. However, there is lack of understanding of magnetic interaction, conduction mechanism inside these ferrites [15,16]. Thus purpose of this review article is to discuss these issues and to give prospects for future research in this direction. SPINEL FERRITEThe general formula for spinel ferrite is MO:Fe2O3 where, M is a divalent transition metal ion. Spinel name is given due to resemblance of structure of these ferrites with mineral spinel MgO.Al2O3. In this structure, oxygen ions are packed quite close together in face centred cubic arrangement and metal ions occupy spaces between them (Fig. 1). These spaces are categorized as tetrahedral (A) and octahedral (B) sites when surrounded by four and six oxygen ions respectively (Fig. 1).In a unit cell of spinel ferrite, there exists 64 and 32 A and B-sites respectively. Only 1/8 th and 1/2 th of A and B-sites are occupied [27]. Metal ions are distributed among A a...

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Section: Electrical and Dielectric Propertiesmentioning

confidence: 71%