Electrosynthesis of samarium hexaboride using tetra borate melt

Abstract

Fine crystals of samarium hexaboride were synthesized by molten salt electrolysis using samarium oxide, sodium tetraborate and lithium fluoride. The electrolysis was performed at 900°C in argon atmosphere at various current densities ranging from 1.0 to 2.3 A/cm 2 . The molar ratio of the reactants [Sm:B] was varied from 1:6 to 1:12. The deposited crystals were examined for the phase purity using X-ray diffraction analysis. The effect of current density and the influence of molar concentration of the reactants were evaluated. The morphological features of the crystals were examined using scanning electron microscopy (SEM). Pure crystals of SmB 6 are obtained at a current density of 1.8 A/ cm 2 . The SEM images reveal that the crystals are packed in a cubic manner, exhibiting irregular morphology. The average crystallite size of the powders is found to be between 72 and 83 nm. The mechanism of formation of SmB 6 is explained by the joint deposition of B and Sm at the Mo cathode.

Electrochemical Synthesis of Magnesium Hexaboride by Molten Salt Technique

“…Jose et al reported the “unstable stoichiometric way” for the deposition of Barium hexaboride [ 14 ]. We reported earlier that the electrolytically dissociated metal and B ions deposit on the cathode as CeB 6 and SmB 6 , respectively [ 15 , 16 ]. We also reported in our earlier study on CaB 6 that the calcium and boron are reduced at the cathode to form submicron sized crystals [ 17 ].…”

Fast identification of the conduction-type of nanomaterials by field emission technique

“…The base pressure of the measurement chamber is lower than 5 × 10 −5  Pa, and the distance between cathode and anode ranges from 100 to 500 μm except individual Si nano-apex (100 nm). UPS (Thermo Fisher Scientific, ESCALAB 250) and Kelvin probe force microscopy (KPFM, Omicron VT-AFM) techniques were respectively used to measure the work function of ZnO 37 , CuO 38 and B 39 nanowires while other one-dimensional nanomaterials adopted the work function of their corresponding bulk counterparts 24,35,39–41 . Their electric conductivity was also obtained by our modified in-situ microprobe measurement technique.…”

Synthesis, densification, microstructure, and mechanical properties of samarium hexaboride ceramic

“…Various processes have been reported for the preparation of SmB 6 powders. Several groups have reported SmB 6 synthesis by reaction of metal (eg, Sm, Sm 2 O 3 , or SmCl 3 ) and boron sources (eg, B, B 4 C, B 2 O 3 , B/C mixture, NaBH 4 , or Na 2 B 4 O 7 ) . SmB 6 particles were synthesized at 1500‐1800°C by borothermal or boro/carbothermal reductions (BCTR) of Sm 2 O 3 with B, B 4 C, or a B/C mixture under vacuum or H 2 .…”