Electrochemical synthesis of lanthanum hexaboride ultrafine particles

Ultrafine powders of pure LaB6 were prepared by the electrochemical synthesis using lantanium- and boron-containing compounds in halide melts. It is shown, that the following interdependent parameters: a total concentration of La and B bearing components, a ratio of La/B and a current density are determinant for the reaction product phase composition. The parameters led to pure LaB6 synthesis were determined as following: (i) temperature is 700 degrees C, duration is 60 min; (ii) total (La + B) concentration is 10(-3) mol/cm(3) and La/B = 1/4; (iii) current density is above 0,6 A/cm(2). The synthesized particles predominantly had round shape with the mean size less than 100 nm. The particles size can be controlled by the current density and total concentration of La and B bearing components.