Precisely controlling RD processes in microfluidic devices enables unconventional reaction pathways in material synthesis. This control facilitates the generation of unprecedented out-ofequilibrium crystal habits and compounds with unique physicochemical properties that differ significantly from those produced through conventional turbulent mixing. Building on this understanding, and before exploring into the formation of the SCO composite fibers, we first evaluated how the continuous flow microfluidic device operating with 3D control over the RD zone can affect the physicochemical properties of the SCO complex, compared to its bulk counterpart generated under turbulent conditions. To this end, we carried out the synthesis of [Fe(Htrz)2(trz)]BF4 without the polymeric matrix in the 3D coaxial flow-focusing microfluidic device.