Structural and Magnetic Studies on Chromium substituted Ni-Zn Nano Ferrite Synthesized by Citrate Gel Auto Combustion Method

Abstract

Nano crystalline Ni 0.5 Zn 0.5 Cr x Fe 2−x O 4 particles with x varying from 0.00 to 0.25 in steps of 0.05 have been synthesized through citrate gel autocombustion method. When Ni 0.5 Zn 0.5 Fe 2 O 4 nano particles were annealed at 1000 o C, the crystallite size increased while the lattice constant decreased slightly. For, the Cr 3+ substituted samples annealed at 1000 o C, the variation in lattice constant, bondlengths, M e -M e distances and other structural parameters have been attributed to the dissimilarity in the ionic radius of the displaced (Fe 3+ ) ion and the substituted (Cr 3+ ) ion. Thermal studies indicated the autocombustion process which is an exothermic reaction between the nitrates salt solutions and the citric acid took place at about a temperature of 400 o C for Ni 0.5 Zn 0.5 Fe 2 O 4 . The M-H loops for all samples indicated a soft ferrite nature for all samples. The non-saturated hysteresis loop and high coercivity for the as prepared Ni 0.5 Zn 0.5 Fe 2 O 4 nano particles has been attributed to the core-shell structure of the fine particles. When annealed at 1000 o C the saturation magnetization of Ni 0.5 Zn 0.5 Fe 2 O 4 nano particles increased and

DC electrical resistivity studies and structure of Ni0.5Zn0.5CrxFe2-xO4 nanoferrites

“…The details of the preparation procedure have been reported in our earlier paper. 8 The as-prepared powders were hand milled for 1 h in an agate mortar and pestle. Powder samples were sintered at 1000 • C in air atmosphere for 2 h with natural cooling to room temperature.…”

“…9 Substitution of Cr 3+ ions of lower ionic radius in the place of Fe 3+ ions have resulted 8 in substantial structural modifications which possibly influence largely the electrical properties of Ni-Zn nanoferrite. Therefore, with reference to the reported results, 8 the present studies on the morphological, microstructural and DC electrical resistivity measurements of chromium substituted Ni-Zn nanoferrite sintered at 1000 • C synthesized by nitrate-citrate gel autocombustion method has been discussed.…”

“…It is well established that the structural, electric, magnetic and dielectric properties of the prepared ferrites are controlled largely by the occupancy of cations among the A-and B-sites. 8 The ceramic route generally employed for developing ferrites suffers from inherent drawbacks which can be eliminated by pursuing wet chemical methods. Amongst these wet chemical procedures, the autocombustion has received remarkable attention since it is rather simple, safe, economical, less time-consuming without requiring the intermediate calcination stage and the products yielded are dry, well crystalline, fine and chemically pure and hence more promising when compared to other methods.…”

Effect of Sintering Temperature on the Micro Strain and Magnetic Properties of Ni-Zn Nanoferrites

“…In our previous communication, we reported the detailed procedure for preparing the Ni-Zn ferrite nanopowders via the citrate-gel autocombustion route [12]. In a typical experiment, citric acid was added to the stoichimetric mixture solution of metal nitrate salts at 65°C under continuous stirring and constant heating.…”

Structural, Magnetic, and Electrical Properties of Ni0.65Zn0.35−x Cu x Fe2 O 4 Nanoferrite System

“…In the past few years, nanostructured Ni-Zn ferrites have been extensively investigated due to their wide variety of applications in various electromagnetic devices such as microwave applications, memory devices, and hard disks [1][2][3]. The properties of these ferrites are highly sensitive to the method of preparation, chemical composition, and sintering temperatures.…”