Ferrite nanoparticles

Fig. 16 Gold-coated ferrite nanoparticles can be attached to functional groups through Au-S bonds. (Credit Charles O Connor)...

It is important to note that in addition to microporous solids, other chemical systems have been used to template the growth of nanomaterials. For example, emulsions have been used to pattern both the pores in titania [14] and the packing of latex particles [46]. Reversed micelles have also been used as patterning agents. Examples include the syntheses of super-paramagnetic ferrite nanoparticles [15] and BaC03 nanowires [47]. Finally, carbon nanotubules have also been used as templates [16,48,49]. A variety of nanomaterials including metal oxides [16,48,49] and GaN have been synthesized inside such tubules [50]. 

This relaxation time—which, to be specific, we have written in the Landau-Lifshitz representation—has the anticipated behavior the smaller the precession damping constant (the higher the quality factor of the oscillations), the slower does the particle magnetic moment approach its equilibrium position. For ferromagnet or ferrite nanoparticles the typical values of the material parameters are Is Is < 103G, Vm 10 18cm3, and a 0.1. Substituting them in formula (4.28) aty 2 x 108 rad/Oe s and room temperature, one obtains xD 10-9 s. 

Ayyappan S, Mahadevan S, Chandramohan P, Srinivasan MP, Philip J, Raj B (2010) Influence of Co ion concentration on the size, magnetic properties, and purity of CoFe204 spinel ferrite nanoparticles. J Phys Chem C 114 6334-6341... 

Soler MAG, Lima ECD, da Silva SW, Melo TFO, Pimenta ACM, Sinnecker JP, Azevedo RB, Garg VK, Oliveira AC, Novak MA, Morais PC (2007) Aging investigation of cobalt ferrite nanoparticles in low pH magnetic fluid. Langmuir 23 9611-9617... 

Han, M., Vestal, C.R. and Zhang, Z.J. (2004) Quantum couplings and magnetic properties of CoCrxFe2-x04 (0 < x < 1) spinel ferrite nanoparticles synthesized with reverse micelle method. /. Phys. Chem. B, 108, 583-597. 

W. Fu, H. Yang, L. Chang, H-Bala, M. Li, G. Zou, Anatase Ti02 nanolayer coating on strontium ferrite nanoparticles for magnetic photocatalyst , CoUoids and Surfaces A Physicochemical Engineering Aspects, 289, 47-52, (2006). 

Figure 11-23. 250- uti wide Ag nanoparticle lines ink-jet printed onto ferrite nanoparticle layer (also ink-jet printed)... 

P. Poddar, J.F. Wilson, H. Srikanth, S.A. Morrison, and E.E. Carpenter, Magnetic properties of conducting polymer doped with magnanese-zinc ferrite nanoparticles. Nanotechnology, 15, S570-S574 (2004). 

Figure 3.155 Transverse relaxivity of various uniformly sized spinel ferrite nanoparticles with respect to composition. t2 correlates strongly with the saturation magnetization Ms [129], Reproduced with permission from Ref [129] 2007, Nature Publishing Group.

P. Xu, X. Han, C. Wang, H. Zhao, J. Wang, X. Wang, B. Zhang, Synthesis of Electromagnetic Functionalized Barium Ferrite Nanoparticles Embedded in Polypyrrole. 7 Phys Chem B 2008,112, 2775-2781. 

NiFe204 Crystallite size 5 nm Particle size 30 nm Water solutions of nickel nitrate or iron nitrate have been mixed with water solution of PAA followed by nitric acid addition. The green color transparent solution have been evaporated at 50 °C until transparent sol, which has been heated at 50 °C for 10 h to brown gel, followed by firing until nickel ferrite nanoparticles formation [130]... 

Gazeau, F, Bacii, J.C., Gendron, F., Perzynski, R., Raikher, Y.L., Stepanov, V.I., Dubois, E. Magnetic resonance of ferrite nanoparticles evidence of surface effects. J. Magn. Magn. Mater. 186, 175-187 (1998)... 

Chen, D.H., Chen, Y.Y. Synthesis of strontium ferrite nanoparticles by coprecipitation in the presence of polyacrylic acid. Mater. Res. BuU. 37, 801-810 (2002)... 

Kahn, M.L., Zhang, Z.J. Synthesis and magnetic properties of CoFe204 spinel ferrite nanoparticles doped with lanthanide ions. Appl. Phys. Lett. 78, 3651-3653 (2001)... 

Grasset, F., Labhsetwar, N., Li, D., Park, D.C., Saito, N., Haneda, H., Cador, O., Roisnel, T., Momet, S., Duguet, E., Portier, J., Etoumeau, J. Synthesis and magnetic characterization of zinc ferrite nanoparticles with different environments powder, colloidal solution, and zinc ferrite-silica core-shell nanoparticles. Langmuir 18, 8209-8212 (2002)... 

Hochepied, J.F., Pileni, M.R Magnetic properties of mixed cobalt-zinc ferrite nanoparticles. J. Appl. Phys. 87, 2472-2478 (2000)... 

Table 15.3 Experimental and theoretical values of saturation magnetization (Ms), magnetic permeability and remnant magnetization (Mr) for the NR/NZF with different concentrations of ferrite nanoparticles.

E. Auzans (1999) Mn-Zn ferrite nanoparticles for water- and hydrocarbon-based ferrofluids preparation and properties. PhD thesis. Institute of Physics, University of Latvia. 

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