Crystal Growth of Silicon hexaboride

In recent years, SiB6, As a P-type high-temperature thermoelectric material, it replaces boron carbide with a hot end temperature of up to 120 °. °C. Currently, there is no good way to synthesize materials and prepare polycrystalline samples. Thermoelectric performance researchers use polythermal samples to prepare their polycrystalline samples. Usually, the Si and B powders are weighed and mixed in a metering ratio, filled in a graphite ink lined with boron nitride (B N ), and hot pressed into a crystal block at 160 ° C and 4 1 x l Pa. Since the 5 1 – B phase diagram is complex, the hot pressed sample is not a single SiB6 phase, and the elemental carbon is at SI B. About 2% solubility, the carbon of the graphite mold will contaminate the sample, so the thermal pressure SiB6. Polycrystalline block composition and purity often do not meet the requirements.

So people thought about preparing SiB6. For single crystals, the anisotropy of thermoelectric properties can be explored using a single product.
We tried to add Cu as the third component to reduce the high temperature volatility of the system, so it can reduce the spontaneous nucleation of the surface, and find is B from the Si-B-Cu ternary system. The formation area of the phase grows SiB6. Single crystal. To this end, we established the SiB6. phase formation zone by high temperature thermal analysis and X-ray diffraction analysis, and then found the suitable growth and growth zone by the seed growth experiment, which grew to a size of SiB6 Single crystal.

Crystal Growth of Silicon hexaboride