<p>key points:<br />- dry every part of the apparatus that will be heated (crucible, reagents, enclosure) for 4h at 150 degC<br />- use lots of NaCl flux<br />- fill crucible with argon before closing it<br />- feed argon into the enclosure from the bottom</p><p>things to improve:<br />- mix NaCl flux with MgCl2 for improved wettability of the oxide<br />- cover the top of the enclosure to somewhat reduce the amount of escaping Mg vapor (as well as heat) with an alumina dish<br />- heat it for several minutes to ensure complete melting</p>