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

[R2-09] Experimental evidence of static disorder of carbonate ions in Ba-doped calcite

*Hiroyuki Kagi¹, Shiho Marugata¹, Yuta Ijichi¹, Kazuki Komatsu¹, Xianyu Xue², Kazumasa Sugiyama³ (1. Univ. Tokyo, 2. Okayama Univ., 3. Tohoku Univ.)

Keywords:amorphous calcium carbonate, barium, calcite, static disorder

Calcium carbonate has three polymorphs: calcite, aragonite, and laterite. The disappearance of the 113 reflection in Ba-containing calcite has been observed at room temperature. Saito et al. (2020) proposed a static disordered state in which the CO₃ ions are arranged in a slightly distorted structure based on molecular dynamics calculations. In this study, Ba-containing calcite samples were used to examine the validity of the static disordered model using a variety of experimental techniques.