SINGLE-CRYSTAL NEUTRON-DIFFRACTION STUDY OF METAMICT ZIRCON UP TO 2000-K

High-temperature single-crystal measurements of metamict zircon were performed up to 2000 K and the recrystallization was monitored using the width and intensity of selected peaks. Full data sets were collected at room temperature, 1573 and 1823 K. The changes in the probability density function (p.d.f.) of the O atoms revealed important features of the recrystallization. The measurements were done in air using a mirror furnace and performed on the D19 four-circle diffractometer at the ILL equipped with a vertically curved two-dimensional position-sensitive detector.