Surface functionalization enhanced magnetism in SnO_2 nanoparticles and its correlation to photoluminescence properties

TL;DR

This study demonstrates that surface functionalization with OTS significantly enhances the magnetic properties of SnO_2 nanoparticles and modulates their photoluminescence, revealing a strong correlation between surface electronic structure, magnetism, and luminescence.

Contribution

It introduces a novel approach of using surface functionalization to simultaneously enhance magnetism and control photoluminescence in SnO_2 nanoparticles, linking surface electronic changes to optical and magnetic properties.

Findings

Surface functionalization increased magnetic moment from 0.08 to 0.187 emu/g.

Functionalization suppressed certain PL peaks and enhanced others.

External magnetic field further modulated luminescence spectra.

Abstract

High value of magnetic moment 0.08 emu/g at room temperature for SnO_2 nanoparticles (NPs) was observed. Surface functionalization with octadecyltrichlorosilane (OTS) enhanced the saturation magnetic moment of NPs to an anomalously high value of 0.187 emu/g by altering the electronic configuration on NPs surface. Surface functionalization also suppressed photoluminescence (PL) peaks arising from oxygen defects around 2 eV and caused an increase in the intensities of two peaks near violet region (2.6 - 3 eV). PL studies under uniform external magnetic field enriched understanding of the role of OTS. Both OTS and external magnetic field significantly modulated the luminescence spectra, by altering the surface electronic structure of NPs. Extra spins on the surface of SnO2 NPs created by the surface functionalization process and their influence on resultant magnetic moment and luminescence properties are discussed in details.