ISIS Neutron and Muon Source Data Journal

Probing Defect-Induced Magnetism in ZnO Nanoparticles via Small Angle Scattering of Polarized Neutron (SANSPOL) and Soft X-ray Techniques

Abstract: ZnO nanoparticles exhibit room-temperature ferromagnetism (RTFM), primarily driven by surface oxygen vacancies and structural defects, rather than magnetic doping. In our recent study, we observed magnetic hysteresis at 2 K in both Co- and Al-doped ZnO nanoparticles, with Al-doped ZnO showing magnetic behavior up to 300 K, despite lacking magnetic ions. ?SR experiments revealed a quasi-static distribution of internal fields, supporting the presence of shallow donor states, while XPS confirmed oxygen-deficient chemical states. These findings suggest defect-driven magnetism, but the spatial distribution of magnetism remains unresolved. To address this, we propose using polarized Small-Angle Neutron Scattering (SANSPOL) to map magnetization profiles at the nanometer scale, isolating magnetic from nuclear scattering. We hypothesize that ZnO nanoparticles have a magnetically ordered core surrounded by a disordered shell, with the shell's magnetism influenced by surface defects. Measurements will be performed on 3 samples at 3 temperatures (2 K, 100 K, 300 K) and across 7 field points, requiring 6 days of beamtime. Complementary soft X-ray measurements at the BLADE beamline at Diamond Light Source will test whether oxygen vacancies or Zn 3d states are magnetically polarized. This research will deepen our understanding of defect-driven magnetism in semiconductor nanoparticles and inform the design of spin-functional nanomaterials for room-temperature applications.

Principal Investigator: Dr Suci Winarsih
Local Contact: Dr Dirk Honecker
Experimenter: Dr Dicky Rezky Munazat
Experimenter: Ms Siti Hindun Hindiyati
Experimenter: Dr Liszulfah Roza

DOI: 10.5286/ISIS.E.RB2520048

ISIS Experiment Number: RB2520048

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Suci Winarsih et al; (2025): Probing Defect-Induced Magnetism in ZnO Nanoparticles via Small Angle Scattering of Polarized Neutron (SANSPOL) and Soft X-ray Techniques, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2520048

Data is released under the CC-BY-4.0 license.