Prenucleation formations in control over synthesis of CoFe2O4 nanocrystalline powders

The minimum size of oxide nanocrystals: phenomenological thermodynamic vs crystal-chemical approaches

“…Some possibilities to expand these methods are based on determining how thermodynamic model parameters, in particular, the specific surface energy, depend on particle size [23][24][25][26][27][28][29][30]. Another possibility is to describe the features of nucleation taking into account the presence in the reaction system of the variously shaped and sized subcritical clusters, which determine the high rate of stable nanoparticles formation in a new phase [10,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48]. However, these approaches do not solve all the problems of describing nucleation processes in the case of a crystalline phase formation.…”

“…On the other hand, as a rule, it is very difficult to experimentally register the minimum possible values of the crystalline particle size due to the rapid growth of nanoscale crystals during phase formation [49][50][51][52], which depends on the conditions of their synthesis [38,42,43,46,[52][53][54][55][56][57][58][59]. Crystal growth can be reduced by using special synthetic methods, which include, in particular, soft chemistry methods, when synthesis proceeds at relatively low temperatures [36][37][38][39][40][41][42][43][44][45][46][47][48][52][53][54][55][56][57][58][59]. Another group of methods that includes, for example, solution combustion, self-propagating high-temperature synthesis (SHS), autocatalytic and other fast solidstate reactions, is based on the use of rapid synthesis [49][50][51][60][61][62][63][64]…”

The effect of microtube formation with walls, containing Fe3O4 nanoparticles, via gassolution interface technique by hydrolysis of the FeCl2 and FeCl3 mixed solution with gaseous ammonia

“…Iron oxides are known to be a significant class of inorganic compounds, which have great potential for practical application [1][2][3][4][5][6][7][8]. Among them, special attention is drawn to Fe 3 O 4 oxide with cubic crystal structure of magnetite and its unique magnetic, electrical and chemical properties [9][10][11].…”

Phase composition and magnetic properties of Ni1-xCoxFe2O4 nanocrystals with spinel structure, synthesized by Co-precipiation

“…The magnetic and electrical characteristics of these ferrites depend on their chemical composition, cation location, particle size, dopant content and the synthesis method [1][2][3][4][5][6][7][8][9]. CoFe 2 O 4 is hard magnetic ferrite with a high coercive force H c > 1500 Oe, with an average saturation magnetization of M s ∼ 40 emu/g [10].…”