2019 年 29 巻 1 号 p. 12-16
We report enantiopure crystal growth and chiral helimagnetic ordering in a chiral inorganic compound CsCuCl3 with a chiral space group of right-handed P6122 or left-handed P6522. Our two-step crystal growth technique makes it possible to grow centimeter sized enantiopure single crystals. First, millimeter-sized seed crystals were synthesized by spontaneous crystallization with stirring. Then, centimeter-sized homo-chiral crystals were obtained from the selected enantiopure seed crystals. Polarized neutron diffraction experiments probed that the right-handed crystal forms purely right-handed helimagnetic structure, and the left-handed crystal forms purely left-handed helimagnetic structure. Therefore, crystallographic chirality of CsCuCl3 strongly combined with helimagnetic chirality via Dzyalloshinskii-Moriya interaction.