Thermal plasma source for processing of MoO3 crystals

Abstract

Simple original technique for fabrication of molybdenum trioxide MoO3 crystals during electric arc discharge directly from metallic molybdenum was proposed. The vertically oriented free-burning arc was ignited between the end surfaces of metallic molybdenum non- cooled electrodes. Molybdenum oxide crystals were deposited on side surface of bottom electrode (anode). Observation of crystals formation zone was used for determination of main process stages. The resulting products were studied by X-rays diffraction and optical microscopy methods. Investigations indicate, that self-organizing vapor-deposition process of MoO3 crystals formation has place. The resulting product is colorless sparkling prisms and platelets, which mainly consist of orthorhombic a-MoO3 phase. Optical microscopy indicates formation of closely packed feather-like pins structures by vapor-solid process.