R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

[R2-12] In-situ observation on the superstructure of a high-pressure phase of hemimorphite

「発表賞エントリー」

*Keitaro Okamoto¹, Takahiro Kuribayashi¹, Toshiro Nagase² (1. Tohoku Univ. Sci., 2. Tohoku Univ. Mus.)

Keywords:Hemimorphite, Pressure-induced phase transition, Secondary building unit, Satellite reflection

We conducted in-situ single-crystal x-ray diffraction experiments with synchrotron radiation on hemimorphite under high-P. At 3.01 GPa, eightfold satellite reflections parallel with b* was observed only near the h+k+l=2n+1 reflections. According to anisotropic displacement parameters of the oxygen sites and pressure dependence of intensities of the satellites, the superstructure of HP-hemimorphite results from perturbation of bond angles within the secondary building units in the b direction.