Structurally related electromagnetic properties of NixFeyO4 nanomaterials synthesized by granulated sodium alginate

On-Line pH Measurement Cation Exchange Kinetics of Y3+-Exchanged Alginic Acid for Y2O3 Nanoparticles Synthesis

“…Three decomposition processes appeared within the temperature ranges of RT 200 °C, 200–300 °C, and 300–450 °C. An endothermic decomposition peak appeared around ~180 °C in the TGA profile, corresponding to an almost 10 wt.% weight loss, which can be attributed to the water evaporation process that occurs during the heat treatment [ 4 , 5 ]. When the temperature was increased further to 300 °C, a weight loss of about 40 wt.% was seen in the TGA profile, corresponding to a small exothermic peak (260 °C) in the DSC profile.…”

“…This significant loss could be attributed to the autocombustion reactions of α-L-guluronic acid (G) and β-D-mannuronic acid (M) in the Y-ALG structure. The release of a significant amount of exothermic energy potentially led to the Y 2 O 3 nanoparticles synthesis [ 4 , 5 ]. No additional weight losses appeared at temperatures exceeding 450 °C, suggesting the completion of the decomposition process ( Figure 4 ).…”

“…The XRD and TEM results with respect to the (111), (220), and (311) crystal planes were quite consistent and agreed well with each other. Errors were more significant in the SAED pattern analysis in comparison to the XRD Rietveld refinement findings because of manual errors that were introduced during analysis of the TEM images, as seen in Figure 6 and Table 3 [ 4 ].…”

“…The crystalline sizes and microstructures were determined through TEM (JEOL JEM-2100F, Tokyo, Japan). Rietveld refinement size-strain structural analysis was conducted to determine the average crystalline sizes of the synthesized Y 2 O 3 samples [ 4 , 5 ]. The specific surface area, pore volume, and pore size of Y 2 O 3 (500 °C) and Y 2 O 3 (800 °C) were measured by BET (Microtrac BEL Belsorp-max, Osaka, Japan).…”

“…The synthesis of metal oxide nanoparticles (e.g., Ce 0.8 Gd 0.2 O 1.90 , NiO-GDC, Ho 2 Zr 2 O 7 , and Ni x Fe y O 4 ) based on sodium alginate gel solutions/granules has been previously developed and reported upon [ 1 , 2 , 3 , 4 ]. The alginate gelation is caused by the interaction that is present between the metal cations and the carboxylate groups in a hydrogel solution, with the cation exchange reaction occurring at a rapid rate [ 5 , 6 ].…”