Chirality-Controlled Enantiopure Crystal Growth of a Transition Metal Monosilicide by a Floating Zone Method

TL;DR

This study demonstrates a laser-diode-heated floating zone method to grow enantiopure transition metal monosilicide crystals with controlled chirality, challenging previous fixed-handedness assumptions and enabling new explorations of chirality-related physical phenomena.

Contribution

The paper introduces a novel crystal growth technique that allows for the controlled synthesis of enantiopure TSi crystals with tunable chirality, expanding possibilities for chirality studies.

Findings

Right-handed CoSi and MnSi crystals were successfully grown from composition-gradient feed rods.

The chirality of the crystals is inherited from the seed part of FeSi used in growth.

The method enables flexible control of crystal chirality, unlike conventional fixed-handedness methods.

Abstract

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 $T$Si ($T$ : 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 have the chirality opposite to that for the crystals in the literature. The LDFZ method with the feed rods with various combinations of $T$Si compounds enables a flexible control of the chirality of $T$Si and will be useful for clarifying the interplay between the crystalline chirality and chirality-induced physical responses.