Solution synthesis of conveyor-like MnSe nanostructured architectures with an unusual core/shell magnetic structure

Abstract

We report for the first time one-dimensional (1D) wurtzite (WZ) MnSe nanoconveyors with a single-crystalline configuration fabricated by a solution-processed colloidal method. High-resolution transmission electron microscopy (HRTEM) measurements show that the stem of MnSe nanoconveyors grows along the [100] direction, while the teeth grow along the [0001] direction. We find that the initial WZ nanobelts with the [100] growth direction are crucial to the formation of nanoconveyors, whereas the teeth are a result of a self-catalyzed growth process induced by the Mn-terminated (0001) surface. The magnetic measurements suggest that 1D WZ MnSe nanoconveyors consist of an antiferromagnetic core and a ferromagnetic shell below the blocking temperature. Furthermore, the hysteresis measurements indicate that these nanoconveyors have 300 Oe coercive fields, which is attributed to the high surface-to-volume ratio of the nanoconveyors. This facile solution-based strategy can be anticipated to synthesize WZ metal chalcogenide nanomaterials with 1D hierarchical structures, for potential applications from spintronics to photocatalysis.