The formation of nanocrystalline orthoferrites of rare-earth elements XFeO3 (X = Y, La, Gd) via heat treatment of coprecipitated hydroxides

Synthesis of GdFeO3 nanoparticles via low-temperature reverse co-precipitation: the effect of strong agglomeration on the magnetic behavior

“…Gadolinium and iron(III) hydroxides undergo a series of physicochemical processes before forming gadolinium orthoferrite and its formation begins immediately after the completion of weight loss [14], therefore the TGA of the co-precipitated hydroxides was necessary to determine the minimum temperature at which GdFeO 3 forms. The TGA and derivative thermogravimetric (DTG) curves are presented in Fig.…”

“…Therefore, nanocrystalline gadolinium orthoferrite seems to be promising as a dual-modal T 1 − T 2 contrast agent for MRI. A variety of methods have been used in the synthesis of GdFeO 3 nanoparticles, including co-precipitation [14], hydrothermal [15], combustion [16], sol-gel [17], microwave [18], and other methods. Among them, the co-precipitation method is a priority for medical applications since it allows the production of gadolinium orthoferrite nanoparticles with minimal chemical impurities.…”

“…Among them, the co-precipitation method is a priority for medical applications since it allows the production of gadolinium orthoferrite nanoparticles with minimal chemical impurities. But the traditional direct co-precipitation technique, routinely realized at room temperature, does not allow to obtain superparamagnetic particles of small (<30 nm) size [14]. Thus, new original approaches are required to solve the synthesis problem of gadolinium orthoferrite nanocrystals with the required crystalline, morphological, and magnetic parameters.…”

Sol-gel synthesis and the investigation of the properties of nanocrystalline holmium orthoferrite

“…The process of formation of agglomerates can be caused by the intergrowth of crystallites, including oriented intergrowth, in the process of nucleation and growth of nuclei, as was shown, for example, in studies [38][39][40] as well as the sintering of nanoparticles during annealing.…”

The use of nanocluster polyoxometalates in the bioactive substance delivery systems

“…There exist various methods for producing nanoparticles [78,80,[87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102] and compositions on their basis. The most common methods for producing nanoparticles include "soft chemistry" methods, including microreactor [98][99][100] and hydrothermal [92][93][94][95][96][97] synthesis, and precipitation (sol-gel method) [87][88][89][90][91]. The methods that are also used include the conductor electric explosion when a high-density current pulse [103][104][105][106][107][108][109][110][111][112][113][114][115] is passed through it; direct laser ablation or ablation in a liquid medium [116][117]…”