Synthesis
BAM powders are produced by heating a nearly stoichiometric mixture of boron, aluminium and magnesium for a few hours at a temperature in the range 900–1500 °C. Spurious phases are then dissolved in hot hydrochloric acid. To ease the reaction and make the product more homogeneous, the starting mixture can be processed in a high-energy ball mill. All pretreatments are carried out in a dry, inert atmosphere to avoid oxidation of the metal powders.
BAM films can be coated on silicon or metals by pulsed laser deposition, using AlMgB14 powder as a target, whereas bulk samples are obtained by sintering the powder.
BAM usually contains small amounts of impurity elements (e.g., oxygen and iron) that enter the material during preparation. It is thought that the presence of iron (most often introduced as wear debris from mill vials and media) serves as a sintering aid. BAM can be alloyed with silicon, phosphorus, carbon, titanium diboride (TiB2), aluminium nitride (AlN), titanium carbide (TiC) or boron nitride (BN).
Read more about this topic: Aluminium Magnesium Boride
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