Phase stabilization of magnetite (Fe3O4) nanoparticles with B2O3 addition: A significant enhancement on the phase transition temperature

Magnetic properties and structural analysis on spinel MnFe2O4 nanoparticles prepared via non‐aqueous microwave synthesis

“…They revealed that Mn 5 O 8 transforms into α-Mn 2 O 3 at 550 °C [64] and Fe 3 O 4 transforms into α-Fe 2 O 3 between 400 and 500 °C. [65] Evidence for the phase separation of MnFe 2 O 4 nanoparticles into α-Fe 2 O 3 and α-Mn 2 O 3 by annealing at 550 °C is also given. [66] A refinement of only the short-range of 1-20 Å (Figure S5a) does not further improve the fit (R W = 0.15), showing that short-and mediumrange order are equivalent.…”

“…The existence of a α ‐Mn 2 O 3 and a α ‐Fe 2 O 3 phase at 600 °C is coincident with earlier studies on the phase transitions of pure iron and manganese oxide nanoparticles as well as manganese ferrite nanoparticles. They revealed that Mn 5 O 8 transforms into α ‐Mn 2 O 3 at 550 °C [64] and Fe 3 O 4 transforms into α ‐Fe 2 O 3 between 400 and 500 °C [65] . Evidence for the phase separation of MnFe 2 O 4 nanoparticles into α ‐Fe 2 O 3 and α ‐Mn 2 O 3 by annealing at 550 °C is also given [66] .…”

Design and Fabrication of a Nanoamorphous Interface Layer in B4C/Al Composites to Improve Hot Deformability and Corrosion Resistance

“…During the deformation of the preoxidized composite, the B 2 O 3 phase is still an amorphous interface layer. With the high-temperature compression deformation, the amorphous interface phase B 2 O 3 turns into molten state at 500 °C, which exhibits a fluid-like feature, that is, it has good fluidity and plastic deformation ability. − Even though the particles break in the deformation process and produce a new surface, it can also be filled by the molten B 2 O 3 without emerging interface gaps caused by the incompatible deformation between the particles and the matrix (Figure (f)), thereby reducing the deformation resistance and improving the hot deformability. In a word, for the B 4 C/Al composites, preoxidation treatment can provide good interface bonding and help to improve the hot deformability.…”

Magnetically Recoverable and Reusable Titanium Dioxide Nanocomposite for Water Disinfection

“…Solutions A and B were then combined in the presence of varying amounts of MS nanocomposite ranging from 12.5 to 70 mg, and the mixture was stirred at room temperature in a shaker shaking at 250 rpm for 48 h. Finally, the samples, referred to as MS-TiO 2 -3 (from pH of 3 media), MS-TiO 2 -7 (from pH of 7 media), and MS-TiO 2 -10 (from pH of 10 media), were rinsed with water, collected magnetically, and dried at 60 • C. The corresponding TiO 2 component control samples were separately prepared by varying the pH and repeating the procedures without the presence of MS nanocomposite. The samples were annealed at 300 • C for 5-7 days to encourage a high degree of transformation of TiO 2 from the assynthesized mostly amorphous phase to anatase while avoiding a potential phase transition of magnetite to hematite at elevated temperatures above 400 • C [31,37,38].…”

“…Annealing was necessary to encourage the formation of the anatase phase, which serves as the photoactive antimicrobial agent. To avoid possible phase changes for magnetite core at temperatures upwards of 400 • C, annealing was completed at 300 • C for 1 week [31,37,38].…”