Thermodynamic investigations on the growth of CuAlO delafossite crystals
arXiv:1709.06776 · doi:10.1016/j.jssc.2017.11.014
Abstract
Simultaneous differential thermal analysis (DTA) and thermogravimetric (TG) measurements with copper oxide/aluminum oxide mixtures were performed in atmospheres with varying oxygen partial pressures and with crucibles made of different materials. Only sapphire and platinum crucibles proved to be stable under conditions that are useful for the growth of CuAlO delafossite single crystals. Then the ternary phase diagram AlO-CuO-Cu and its isopleth section CuO-AlO were redetermined. Millimeter sized crystals could be obtained from copper oxide melts with 1-2 mol % addition of aluminum oxide that are stable in platinum crucibles held in oxidizing atmosphere containing 15-21 % oxygen.
12 pages, 7 figures