NaCl-Assisted Growth of Ferroelectric SnSe Nanosheets with Spin Glass-like Behavior

TL;DR

This paper reports a NaCl-assisted CVD method to synthesize high-quality 2D SnSe nanosheets exhibiting ferroelectricity and spin glass-like magnetic behavior, with implications for future ferroelectric applications.

Contribution

It introduces a controllable synthesis route for SnSe nanosheets and characterizes their ferroelectric and magnetic properties for the first time.

Findings

NaCl significantly increases surface coverage of SnSe nanosheets.

Ferroelectric domains are directly visualized in SnSe nanosheets.

Weak ferromagnetism and spin glass-like behavior are observed at low temperatures.

Abstract

Two-dimensional (2D) SnSe is an emerging 2D material exhibiting intriguing properties such as ferroelectricity and nonlinear optical response. Here, high-quality single-crystalline SnSe nanosheets were synthesized via NaCl-assisted chemical vapor deposition (CVD) method. The addition of NaCl was found to significantly increase the surface coverage of the nanosheets with less influence on their lateral size. The crystalline structure and composition of as-grown nanosheets were charactered by XRD, Raman spectroscopy, and XPS. Ferroelectric domains in SnSe nanosheets are directly visualized by piezoresponse force microscopy (PFM). The magnetic hysteresis loops of SnSe nanosheets are achieved at 2 K, which indicated their weak ferromagnetism. A spin glass-like behavior was observed below 115K, which is attributed to the presence of SnSe2 impurity. This work further establishes a controllable synthesis route for SnSe nanosheets, thereby paving the way for subsequent investigation of their ferroelectric properties.