Growth of single-crystalline SmB₆ nanowires and their emperature-dependent electron field emission

A facile catalysis-free method has been utilized to synthesize functional samarium hexaboride (SmB6) nanowires. Structural characterization shows that the nanowires are single-crystalline SmB6 with the [1 0 0] growth direction. These nanowires exhibit a low turn-on electric field of 4.2 V μm-1 based on the 10 μA cm-2 current density criterion at room temperature (RT). The effect of temperature on the field emission properties of the SmB6 nanowires has also been investigated. The turn-on field of the SmB6 nanowires is found to decrease from 4.2 to 2.7 V μm-1 (at 10 μA cm-2); meanwhile, the estimated field enhancement factor increases from 2207 to 4741 clearly with an increase from RT to 573 K. This dependence might be due to the change in the effective work function of the nanowires with temperature.