Room temperature agglomeration for the growth of BiTeI single crystals with a giant Rashba effect

We report a room temperature agglomeration (RTA) procedure to grow highly homogeneous and impurity-free BiTeI single crystals safely. The proposed four-step procedure of mixing and heating is able to prevent severe iodine loss and avoid the danger of explosion during large scale crystal growth. Following the RTA treatment of the precursor, the single crystals obtained from three different growth methods, including vertical Bridgman, melt growth and chemical vapour transport (CVT), were compared. Crystals grown using the Bridgman method showed the highest residual-resistance ratio (RRR) and mobility, and the largest domain size among the three. The crystal quality and purity have been confirmed using X-ray diffraction, Electron Probe Microanalysis (EPMA), resistivity, TEM, and STM. Additionally, Mn-intercalated and -substituted BiTeI crystals have also been investigated. We report a room temperature agglomeration (RTA) procedure to grow highly homogeneous and impurity-free BiTeI single crystals safely.