Dielectric relaxation, conductivity behavior and magnetic properties of Mg substituted Zn–Li ferrites

2012

Soft nanoferrites of nominal composition Mn 0.5 Cu x Zn 0.5−x Fe 2 O 4 with 0.0 ≤ x ≤ 0.35 were prepared by chemical co-precipitation method. The formation of single phase spinel structure with different compositions, sizes and macrostructure were confirmed by X-ray diffraction patterns and scanning electron microscopic (SEM) measurements. The lattice parameter decreased with increase in Cu 2+ content. The crystallite size of the powder samples varied from 14 to 27 nm. The theoretical density increased with increase in Cu 2+ content. Room temperature saturation magnetization was measured as a function of copper content. The saturation magnetization (Ms) and Bohr magneton (μ B ) increases up to x = 0.25 due to increased A-B interactions in the AB 2 O 4 type spinel nanoferrites. Dielectric permittivity, dielectric loss tangent and complex impedance plots were studied in the frequency range 20 Hz-5 MHz. Loss peak occurs for all the studied compositions and shifts towards low frequency with increased Cu 2+ content. Complex impedance spectroscopic studies confirmed that conduction in the samples is due to grain boundaries. The high values of DC electrical resistivity support this result.

Section: Magnetic Studiessupporting

confidence: 92%

Structural, Magnetic and Electrical Properties of Cu Substituted Mn–Zn Soft Nanoferrites

Anwar

2012

“…The results obtained are in agreement with previous studies of ferrites containing Mn, Cu, or Ni ions [24][25][26][27][28][29][30]. In calculating the magnetic moment (n B ), we have to consider A-B interaction and cation distribution.…”

Section: Electrical Propertiessupporting

confidence: 92%

Synthesis, Structural, Electrical, Magnetic Curie Temperature and Y–K Angle Studies of Mn–Cu–Ni Mixed Spinel Nanoferrites

Faraz

2011

Nanoferrites of composition Mn 0.50 Cu 0.5−x Ni x Fe 2 O 4 (0.00 ≤ x ≤ 0.50) are prepared by chemical coprecipitation method. The prepared nano-ferrites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), two probe resistivity apparatus, and vibrating sample magnetometer (VSM) to study the compositional, structural, morphological, electrical, and magnetic properties with varying concentration (x) in the composition of the prepared nanoferrites. XRD confirmed formation of single phase spinel ferrite with crystalline size in the range of 16-29 nm. The lattice parameter (a) decreases with a decrease of Cu concentration. Further information about the structure and morphology of the nanoferrites was obtained from SEM and results are in good agreement with XRD. FTIR gives information about distribution of cations and anions by confirming the presence of high and low frequency bands due to tetrahedral and octahedral sites, respectively. The electric properties were measured and analyzed by using homemade two probe resistivity apparatus showing semiconducting behavior of synthesized ferrites. The magnetic hysteresis curves clearly indicate the soft nature of the prepared samples. Various magnetic parameters such as saturation magnetization (M s ), and remanence (M r ) are calculated from the hysteresis loops and observed compositional dependent. Saturation magnetization and magnetic moment increase with Ni content. This is due to the existence of localized canted spin. Coercivity and A. Faraz ( ) · A. Maqsood

“…The increase in the value of M s and M r with decrease in Mg concentration can be explained on the basis of Neel's theory [29]. The results obtained are also in reasonable agreement to previous studies of ferrites containing Mn, Mg, or Ni ions [30][31][32][33].…”

Section: Electrical Propertiessupporting

confidence: 79%

Synthesis, Structural, Electrical and Magnetic Characterization of Mn0.5Mg0.5−x Ni x Fe2O4 Spinel Nanoferrites

Faraz

2011

Nanoferrites of composition Mn 0.50 Mg 0.5−xNi x Fe 2 O 4 with 0.00 ≤ x ≤ 0.50 were prepared by the chemical coprecipitation method. The prepared nanoferrites were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), atomic force microscopy(AFM), dc electric resistivity and magnetic properties using vibrating sample magnetometer (VSM) to study the structural, morphological, electrical, and magnetic changes taking place with varying Ni and Mg concentration in the composition of the prepared nanoferrites. The XRD results indicated the formation of single spinel ferrite with crystalline size in the range of 16-24 nm. The lattice parameter (a) decreased with the decrease of the Mg concentration. IR reveals the presence of both high and low frequency bands due to tetrahedral and octahedral sites, respectively. Further information about the morphology of the nanoferrites was obtained from AFM and SEM measurements. Electrical properties indicate that synthesized samples have high resistivity. The magnetic hysteresis curves clearly indicate the soft nature of the prepared nanoferrites. Various magnetic parameters such as saturation magnetization (M s ), and remanence (M r ) are obtained from the hysteresis loops and observed to be dependent on the composition.