Structural studies for Zn_xMg_0.8-xNi0.2Fe₂O₄ ferrites

Abstract

A series of samples of the system ZnIMgo.8-,N~.2Fe~04 (with x=0,0.2,0.4,0.6 and 0.8), was prepared using the usual ceramic technique. The samples were studied using X-ray diffraction, DTA, TG, TGA and IR spectroscopy. The lattice constant, radius of tetrahedral ion, X-ray density and measured bulk density are found to increase while porosity decreases as zinc ion content increases. Both TG and TGA spectra show two exothermic phases at the magnetic T, and Curie T, transition temperatures while DTA does not indicate any exothermic processes. The transition temperatures were found to increase as Zn ion content decreases. The four IR bands speclfyig femtes are observed whose intensities and positions are composition dependent.

Structural and magnetic susceptibility studies of samarium substituted magnesium–zinc ferrites

“…It is observed that the position of the band 2 shift towards the lower frequency, which confirms the occupancy of Sm 3+ ions on the octahedral site. The similar results have been reported for rare-earth element substituted for Ni-Zn [18], Cu-Cd [19], and Zn-Ni-Mg ferrites [3]. This may be due to atomic mass and volume of the dopant, which affect Fe-O distances on octahedral sites, suggesting that Sm 3+ ions occupied octahedral lattice sites.…”

“…Another low frequency band 4 appears for all the compositions (except for composition x = 0.8 for y = 0.05, x = 0.2, 0.4 for y = 0.1), which depends on the mass of the divalent tetrahedral cation and is related to some type of vibrations involving a displacement of tetrahedral cation [24]. It is observed that the intensity and band position are the composition dependent [3,21].…”

“…These properties of ferrites are strongly depending on their chemical composition, cation distribution, method of preparation in general and structure in particular [2,3]. The microstructure, porosity and grain size of ferrites play an important role in deciding the ac susceptibility [4].…”

Effect of Sm 3+ –Gd 3+ on structural, electrical and magnetic properties of Mn–Zn ferrites synthesized via combustion route

“…The difference between absorption bands n 1 and n 2 is due to changes in bond length (Fe 3þ -O 2À ) at tetrahedral and octahedral sites [24]. Here we can observe slight change in band position in n 1 and n 2 this difference is due to the method of preparation, grain size and porosity can influence in locating the band position [25,26]. The difference between the spectra upon increasing the amount of dopant elements this is may be due to the increase of the amount of undesired Fe, Gd and Sm oxides in material.…”

Effect of Sm3+-Gd3+ co-doping on dielectric properties of Mn-Zn ferrites synthesized via combustion route

“…Here we can observe slight change in band position in ν 1 and ν 2 this difference is due to the method of preparation, grain size and porosity can influence in locating the band position [23]. It can be seen that the absorption band ν 1 not shown any splitting or shoulders and hence the possibility of Fe 2+ ions at A-sites is ruled out [24].…”