Optimization of preparation parameters and characterization of the Mn0.5Zn0.5Fe2O4 thermal-sensitive magnetic ferrofluid prepared by the hydro-thermal method
The bare magnetic Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanoparticles were prepared by the hydro-thermal method. The optimized preparation conditions were obtained by the orthogonal experiment. Crystal structure and the grain diameter of the particles were observed by X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM), and the Curie temperature of the bare particles and the performance of the magnetic moment of the particles at different temperatures were characterized by the Vibrating Sample Magnetometer (VSM). The bare particles were modified by the oleic acid, and the modification effect was verified by the Infrared Test (IR). Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive magnetic ferrofluid with excellent performance were prepared by dissolving the modified particles in the kerosene carrier. The saturation magnetization could reach up to 278Gs and the Curie temperature is confirmed to be 322K, which indicates that the quality of the Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive ferrofluid is better than other Mn<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> thermal-sensitive ferrofluids prepared by the coprecipitation method previously reported (Saturation magnetization: 150Gs, Curie temperature: 340K[1]).
Production and Application of Thermal Ferrite
Thermal ferrite at curie temperature 93 ℃ is made by suing ceramic process technology.Introduce teh production equipmetns and material.Analyse and discuss effective factors on material curie temperature and yield.Finally introduce principle and application of thermal magnetic switch.
The preparation of MnZn-ferrite nanoparticles in water-CTAB-hexanol microemulsions
Magnetic MnZn-ferrite nanoparticles with a narrow size distribution were prepared in water–CTAB–hexanol microemulsions. The region of microemulsion stability in the system was determined, using the titration method, as a function of the temperature and of the type and concentration of solutes in the aqueous phase. The nanoparticles were prepared in a two-step process: the precipitation of the corresponding hydroxides, followed by oxidation of the Fe2+. The particle size was controlled by the composition of the microemulsion and the concentration of the reactants (the corresponding sulfates and a precipitation agent, tetramethyl ammonium hydroxide) in the aqueous solution of the microemulsion. The specific magnetization of the nanoparticles (measured at 13 kOe) was found to depend mainly on particle size: ranging from 1.3 emu g−1 for particles of approximately 2 nm in size to 7.3 emu g−1 for particles of approximately 5 nm in size.