Nanomaterials @ Interfaces Research Group

We report an ¹¹⁹Sn nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) study of cubic π-phase SnS semiconductor nanoparticles. The data are compared with orthorhombic α-SnS. The NMR spectrum of cubic SnS reveals two inequivalent tin atoms in its crystal structure. The spin-lattice relaxation time of ¹¹⁹Sn nuclei in the cubic phase is much longer than that in the orthorhombic phase, indicating that the former is mainly governed by Raman scattering, while the latter is dominated by interaction of nuclear spins with unpaired electron spins of paramagnetic defects. This is supported by EPR measurements showing much larger content of paramagnetic defects in the orthorhombic phase compared with the cubic phase. The study provides novel research findings on the physical properties of the newly discovered cubic π-SnS, which is an emerging semiconducting material system for various applications.