MÖSSBAUER STUDY OF In³⁺ AND Al³⁺ ADDITIVES IN Mg–Mn FERRITES

Abstract

The effect of In 3+ and Al 3+ substitution in Mg-Mn ferrite has been studied from Mössbauer analyzes of Mg 0.9 Mn 0.1 MxFe 2−x O 4 (0 ≤ x ≤ 0.9) and Mg 0.9 Mn 0.1 Fe 2−y O 4 (0 ≤ y ≤ 0.5) ferrites. The internal magnetic field has been found to decrease at tetrahedral and octahedral sites when the concentration of In 3+ and Al 3+ ions is successively increased. A ferromagnetic relaxation followed by paramagnetic transition is observed for higher concentrations of In 3+ ions, it has been inferred that a larger concentration of In 3+ ions enhances relaxation effects. The observed values of isomer shift corresponding to Fe 3+ ions at A as well as B sites in both the series show an insignificant variation with increase in the concentration of In 3+ and Al 3+ ions. It is also inferred that all the samples show negligible value of quadrupole splitting with in experimental errors. The occupancy ratio increases with increase of In 3+ ions and the occupancy ratio decreases with increase of concentration of Al 3+ ions. The results of occupancy of Fe 3+ ions at B to A site, as obtained from Mössbauer studies are in conformity with the cation distribution used to explain variation of 4πMs and µ 0 .

Magnetic study of substituted Mg–Mn ferrites synthesized by citrate precursor method

“…In 3+ ions preferentially occupy the tetrahedral site [10], Al 3+ ions have a strong affinity to occupy the octahedral site [23] and Co 2+ ions preferentially occupy B site [24] but the increase in n B with increasing substitution of Co is attributed to the high exchange interaction energy and relatively higher orbital contribution of Co for the magnetic moment. In the case of increased In 3+ substitution, as the Fe 3+ (B)/ Fe 3+ (A) ratio increases which increases saturation magnetization and therefore n B increases, but with increasing Al 3+ ions, Fe 3+ (B)/Fe 3+ (A) ratio decreases and therefore the magneton number, n B , decreases.…”

“…It has been reported that in Mg-Mn ferrite if Fe ions are replaced by In [4,9,10], Al [1,4,10] and Co [11], the magnetic properties are modified. The citrate precursor method [12][13][14][15][16] ensures ease of preparation and control of composition, particle size, purity, homogeneity and uniform grain growth.…”

Probiotics as Biotherapeutic Agents: Present Knowledge and Future Prospects

“…The role of the gut microflora in the maturation of the mucosal immune barrier is regarded as predominant and expected to take place in the first years of life [44,45,46,47]. It is suspected that the increasing incidence of allergic diseases, seen among children of industrialized countries, is connected to their difficulty to establish a satisfactory protective endogenous gut flora, possibly as a consequence of a lowered consumption of foods produced by natural fermentation [39,44,45], along with a decreased contact with pathogens due to the increased hygienic conditions of modern housing [48][49][50][51]. These modified food habits along with modern life styles and changed environmental conditions have been cited as causes of stress that predispose humans to inflammatory, ulcerative, degenerative, auto-immune and infectious diseases [39].…”

Effect of Sintering Temperature on Electrical Properties of Mn0.5Zn0.5Fe2O4 Nanoscale Particles Prepared by Co-Precipitation Method

“…In this paper, magnetic and electrical properties of Mn 0.5 Zn 0.5 Fe 2 O 4 are discussed thoroughly. The performance of any ferrite is greatly influenced by its synthesizing technique [7][8][9][10][11][12][13]. The conventional ceramic method of preparation which involves solid state reaction between oxides at high temperatures is cumbersome, time consuming and does not always result in pure reproducible product.…”

“…The conventional ceramic method of preparation which involves solid state reaction between oxides at high temperatures is cumbersome, time consuming and does not always result in pure reproducible product. Therefore, various non-conventional processing techniques [7][8][9], which are mainly solution techniques are reported. In the present work nonconventional preparation method, known as co-precipitation method, was used for preparation of Mn Zn ferrite.…”