抄録
Phase transition from orthoenstatite (Pbca-form) to high-clinoenstatite (C2⁄c-form) was first found by the in situ observation at above ∼1200°C under a transmission electron microscope [TEM]. Upon heating the orthoenstatite specimens, (100) stacking faults abruptly appeared at above ∼1100°C, and high-clinoenstatite was designated in the diffraction pattern at above ∼1200°C. The transition from orthoenstatite (O) to high-clinoenstatite (C) occurred with the topotactic relations of ao⁄⁄ac*,bo⁄⁄bc, and co⁄⁄cc. These facts indicate that the (100) intergrowth of high-clinoenstatite occurred on a very fine scale in the parent phase of orthoenstatite at high temperatures.
