Melt-assisted synthesis to lanthanum hexaboride nanoparticles and cubes

Abstract

Lanthanum hexaboride (LaB6) nanocrystals and cubes were successfully synthesized at 700°C for 2 h under argon atmosphere by a melt-assisted method using LaCl3 and NaBH4 as reactants, NaCl-KCl or zinc or NaCl-KCl-zinc as reaction melt. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. XRD patterns and Raman spectra confirmed the formation of LaB6 with high purity. TEM and SEM results showed LaB6 powders prepared in mixed molten salts of NaCl-KCl were mainly composed of nanoparticles with sizes of ca. 8 nm. The morphology of LaB6 presented as regular cubes (100-300 nm) when metal zinc was used as reaction melt. Photothermal conversion test indicated that nanoparticles had a better photothermal conversion performance than cubes.