Chirality-controlled enantiopure crystal growth of a transition metal monosilicide by a floating zone method

We performed a crystal growth to obtain chirality-controlled enantiopure crystals using a laser-diode-heated floating zone (LDFZ) method with a composition-gradient feed rod. It has been argued that the crystal handedness of TSi (T : transition metal) is fixed depending on T in the case of the ones grown by the conventional methods. We found that right-handed single crystals of CoSi and MnSi were grown from the composition-gradient feed rods that consist of FeSi-CoSi and FeSi-MnSi, respectively. The obtained CoSi and MnSi crystals inherit the chirality from the seed part of FeSi, which grows in a right-handed structure, and thus has the chirality opposite to that for the crystals in the literature. The LDFZ method with the feed rods with various combinations of TSi compounds enables flexible control of the chirality of TSi and will be useful for clarifying the interplay between crystalline chirality and chirality-induced physical responses.