Conditions for the growth of Fe1−xO crystals using the micro-pulling-down technique

Small wüstite (Fe1−xO) crystals were grown using the micro-pulling-down technique. Eutectoid decomposition of the grown crystals was suppressed by fast cooling associated with fast crystal pulling at a rate of 50 mm/min. Crystals grown at lower rates contained magnetite as a second phase indicating the beginning decomposition. Additionally, in those crystals the original wüstite of near-eutectoid composition (x≈0.05) was decomposed into two wüstite phases of which one was iron-poor, x≈0.09, the other instead iron-rich, near-stoichiometric, x≈0.02.