Synthesis of Sn (1−x) Fe x @FeySn (1−y) O z nanohybrids via a simple programmed microfluidic process

Core–shell Sn (1−x) Fe x @Fe y Sn (1−y) O z nanohybrids are synthesized via a simple programmed microfluidic process. Characterization by high resolution transmission electron microscopy, energy dispersion X-ray spectroscopy and X-ray diffraction indicates that their sizes, shapes, compositions and crystal structures can be conveniently tuned by reaction temperatures. Different from the orientated growth to rod shaped Sn (1−x) Fe x @Fe y Sn (1−y) O z nanorods ( x ≪ 0.1, y < 0.5) with tin-rich crystalline cores and amorphous shells mixing with tiny Fe@FeO x nanoparticles at a low reaction temperature ( e.g. , 30 °C), the Sn (1−x) Fe x @Fe y Sn (1−y) O z nanospheres ( x < 0.5, 0.5 ＜ y < 1) with crystalline tin-rich FeSn alloy cores and surface oxidized tin ferrite shells can be formed at an elevated reaction temperature ( e.g. , 90 °C). A blue-shift was found in the photoluminescence spectrum due to the existence of Fe in Sn (1−x) Fe x @Fe y Sn (1−y) O z nanospheres compared with those Sn@SnO 2 nanohybrids. The superparamagnetic property observed in the nanospheres can be attributed to the SnFe alloy cores and amorphous tin ferrite shells. As to the portion of Fe doping of Sn@SnO 2 nanorods mixed with Fe@FeO x nanoparticles formed at 30 °C, they exhibit paramagnetic properties with increased saturated magnetic fields.