Enhanced magnetic properties of Fe3+ doped ZnS nanocrystals via low temperature co-precipitation: spintronic and nano-device applications

The present work emphasises synthesis and characterization of undoped and Fe3+ doped ZnS nanocrystals. The prepared samples are synthesized by simple co-precipitation technique. The recorded XRD pattern confirms the cubic structure of prepared samples and its estimated average crystallite size is 3–3.5 nm range, and also evaluated micro-structural parameters. SEM images of prepared samples exhibit granular structure with spherical particles and non uniform in shape, size where as Fe3+ doped sample is more agglomerated. TEM images of undoped sample depicted rod like structures where as Fe3+ doped sample exhibits spherical shaped structures. The energy bands obtained in UV–vis region from optical absorption spectrum are recognized as characterstic bands of Fe3+ ions and also evaluated the crystal field, inter electronic parameters (Dq, B and C). EPR spectrum of Fe3+ doped sample exhibited a strong signal at g = 2.136. Photoluminescence spectrum of undoped sample is witnessed by strong blue emission band at 421 nm where as Fe3+ doped ZnS has an additional weak peak observed at 609 nm (4T2 → 6A1). The evaluated CCT values are 2568 K for ZnS and 3079 K for Fe3+ doped ZnS. VSM analysis reveals the observation of enhanced magnetism for Fe3+ doped ZnS nanocrystals compared to undoped sample ZnS. Thermal analysis signifies that the prepared samples are stable upto 888 °C (ZnS) and 993 °C (Fe3+ doped ZnS). The prepared materials may suitable for the various device applications in nanoscale magnetic, optical-spintronic devices and led to fabricate DMS materials for new trending applications.