Structural and thermal studies of Ni0.25Mn0.75Fe2O4 composites by sol–gel combustion method

Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

“…6A) are also observed in DSC curves. The similar phenomenon of the auto-catalyzed oxidation of citrate happened in the presence of nitrate has been reported in literature [54][55][56]. There is no significant weight loss above 350 • C, indicating that the calcination temperature at 400-900 • C for 1Cu9Mn/SBA-15 precursor is almost reasonable.…”

Effect of Ni substitution on the structural and transport properties of NixMn0.8−xMg0.2Fe2O4; 0.0≤x≤0.40 ferrite

“…3 for samples Ni x Mn 0.8−x Mg 0.2 Fe 2 O 4 (0 ≤ x ≤ 0.40) recorded in the range of 200-800 cm −1 . As usual for spinel ferrites, the band 1 from 633 to 692 cm −1 arises due to the tetrahedral metal-oxygen bond (Fe 3+ -O 2− ) tetra and 2 from 582 to 584 cm −1 is due to the octahedral metal-oxygen (Fe 3+ -O 2− ) octa and these two bands are characteristic for Ni-Mn ferrite as reported elsewhere [11][12][13][14]. Also, it has been reported that [15], Fe 3+ -O 2− distance for A-site (0.189 nm) is smaller than that of B-site (0.199 nm).…”

Low-temperature synthesis of nanocrystalline NiCuZn ferrite and the effect of Cr substitution on its electrical properties

“…The values of quadrupole splitting for samples with chromium content up to 0.6 have been found to be negligibly small indicating the presence of cubic point symmetry [31]. It is clear from Table 2 that non-zero quadruple splitting in the Mössbauer spectra of samples with x Z0.8 is attributed primarily to the paramagnetism, which in turn results in chemical disorder [22].…”