Microstructure, growth mechanism and anisotropic resistivity of quasi-one-dimensional ZrTe5 crystal

The study of ZrTe5 is revived because theory predicts the quantum spin Hall effect in monolayer ZrTe5 and topological phase in bulk ZrTe5. To study the topological property of ZrTe5, the growth of large size and high-quality single crystals is the first and crucial step. Here, by mean of iodine (I2) transport agent, centimeter-sized ZrTe5 single crystals were successfully grown by the chemical vapor transport technique. The microstructure characterization reveals that grown ZrTe5 crystal has “stacking stripes of wood” morphology, and growth mechanism is proposed accordingly. The size of grown ZrTe5 crystals can be reached as large as 35×2×0.5 mm3, which enable us to measure the a-, b- and c- axis anisotropic resistance. Large and single crystalline ZrTe5 crystals provide a solid basis for exploring its topological phase.