Structural and magnetic characterizations of MnNiZn ferrite nanoparticles

Abstract

The ferrite samples of Ni0.7−xMnxZn0.3Fe2O4 (where x = 0.0–0.7 in steps of x = 0.1) were synthesized by a sol–gel autocombustion method using nitrates of respective metal ions. The synthesized samples were annealed at 600 °C for 4 h. The phase purity of the samples was investigated by X‐ray diffraction (XRD). An analysis of XRD patterns reveals the formation of single‐phase cubic spinel structure. The crystal lattice constant increases gradually with increasing x from 8.389 to 8.473 Å. The cation distribution of constituent ions shows linear dependence of Mn substitution. Based on the cation distribution obtained from XRD data, structural parameters such as lattice parameters, ionic radii of available sites, and the oxygen parameter “u” have been calculated. The trend of theoretically calculated lattice parameter with Mn content matches well with the experimentally obtained values. An initial increase followed by a subsequent decrease of saturation magnetization with increase in x is observed. Possible explanations for the observed structural and magnetic behavior with various Mn content are discussed.

Effect of Mn2+ and Cd2+ on the Physical Properties of Li-Mixed Spinel Nanoferrites

“…The non-magnetic Cd 2+ content strongly influence the Bohr magneton values and it is observed that initially, the incorporation of non-conducting Cd 2+ leads to increase n B values up to x = 0.30 with further incorporation causes decrease in n B values due to the weakness in strength of A-B site interaction and greater non-magnetic behavior [26]. The values of n B for all the samples are listed in Table 2 and is represented in Fig.…”

“…This non-zero Y-K angle values determine that the synthesized material behavior cannot be explained on the basis of Néel's sub-lattice model. The values of Y-K are calculated with the standard relation [26] The values of Y-K angle calculated at room temperature are found in range 39-84°, indicate that Cd 2+ content influence Y-K angle and are attributed due to spin canting. Effect of dopant Cd 2+ concentration on Curie temperature is represented in Fig.…”

“…It is observed that the coercive force (H c ) values decrease up to x = 0.30 and then increase occurs. This may be attributed due to magneto anisotropy effect[26]. Magnetic ratio (M r /M s ) is calculated and found in the range 0.26-0.29.…”

“…Magnetic ratio (M r /M s ) is calculated and found in the range 0.26-0.29. The Bohr magneton calculated using the standard relation[26] n B = moleculer weight (M.W ) × saturation magnetization (M s ) 5558 × measured density (ρ m )…”

Effect of temperature on structural, morphological and magnetic properties of Cd0.7Co0.3Fe2O4 nanoparticles

“…From the values of coercivity (Hc) and the saturation magnetization (Ms), the value of the anisotropy constant, K, can be calculated using the following relation [37]: The magnetization increases with increasing annealing temperature, which may be explained as follows. (i) The grain size of the prepared material increases, and the microstructure becomes well crystallized.…”