Samarium borides exhibit unique electrical and magnetic properties that have potential applications in a number of fields. However, it is still challenging to obtain crystalline samarium borides with controllable stoichiometry and morphology by simple synthetic methods. Herein, we report the one-pot synthesis of two samarium boride phases via the reactions between samarium halides and NaBH₄ in molten LiCl-KCl. The stoichiometry and morphology were controlled by varying the precursor ratio and reaction time. The crystalline SmB₄ possesses rod-shaped structure with diameters around 60–90 nm, and nanocubes around 50–100 nm were obtained for SmB₆. On the basis of XRD and SEM results, the SmB₄ nanorods obtained at a Sm/B ratio of 1:3 evolve from the initially formed SmB₄ nanofilms, while formation of the SmB₆ nanocubes at a Sm/B ratio of 1:10 is mediated by SmB₄. The transition from film-shaped SmB₄ to cubic SmB₆ most likely results from the destruction of the SmB₄ nanocrystal upon partial reduction of Sm³⁺ to Sm²⁺ in the presence of excess NaBH₄, which is consistent with the change in oxidation state of samarium from XANES analysis. The SmB₄ nanorods and SmB₆ nanocubes synthesized in molten salt possess similar paramagnetic properties to those obtained by other methods, which demonstrates the capability for the facile synthesis of lanthanide borides with controllable stoichiometry and morphology in molten salt under mild conditions.

硼化exhibit具有独特的电和磁性能，在许多领域都有潜在的应用。然而，通过简单的合成方法获得具有可控的化学计量和形态的结晶硼化still仍然具有挑战性。在这里，我们报告了通过卤化mar和NaBH ₄在熔融的LiCl-KCl中的反应，一锅法合成两个硼化phase相。通过改变前体比和反应时间来控制化学计量和形态。结晶SmB ₄具有直径约为60-90 nm的棒状结构，并且SmB ₆获得了约50-100 nm的纳米立方体。根据XRD和SEM结果，SmB ₄以Sm / B比为1：3的纳米棒从最初形成的SmB ₄纳米膜演化而来，而以Sm / B比为1:10的SmB ₆纳米立方的形成是由SmB ₄介导的。从膜状SmB ₄到立方SmB ₆的转变最可能是由于在过量的NaBH ₄存在下将Sm ³⁺还原为Sm ²⁺而将SmB ₄纳米晶体破坏的结果，这与氧化变化是一致的XANES分析得出的状态。SmB ₄纳米棒和SmB ₆ 在熔融盐中合成的纳米立方体具有与通过其他方法获得的相似的顺磁性能，这表明在温和条件下在熔融盐中易于合成化学计量和形态可控的镧系元素硼化物。