The invention relates to synthesis of nanoparticles, in particular to methods for producing nanoparticles with a net-works consisting of Z sulphate (Z=magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) or the binary mixtures thereof). The inventive method consists in synthesising the nanoparticles by crystal growth from an ion Z source and a sulphate ion source in a synthesis liquid phase mixture. The aim of said invention is to produce in a simple way barium sulphate nanoparticles having a small diameter, said particles being uniformly dispersed in water or other solvents. For this purpose, co-ordinating solvents like glycerine, glycol ethylene and other polyethylene glycols, polyalcohols or dimethylsulphoxide (DMSO) are used for the synthesis mixture. In the preferred embodiment, barium is used in the form of chloride and the sulphate source in the form of tetrabutylammonium hydrogen sulphate. Other metallic dopants can be eventually integrated in the nanoparticles network. When the synthesis is also used in the form of chloride.