Fabrication and Characterization of Na-filled Prussian Blue Nanoparticles
Yu-Shuan Huang1*, Chi-Hung Lee1, Chun-Yu Tsai1, Erdembayalag Batsaikhan1, Chang-Xhuan Yang1, Shih-Chieh Tai1, Chia-Tsun Chen1, Bo-Yong Wu1, Wen-Hsien Li1
1Department of Physics, National Central University, Chungli, Taiwan
* presenting author:Yu Shuan Huang, email:rayhuang700@gmail.com
Prussian blue analogue with a chemical formula of NaxFe[Fe(CN)6]y[(H2O)6]1-y·zH2O (Na-Fe-Fe) crystalizes into a face-centered cubic structure. It provides large enough voids at the center portion of the lattice to accommodate sodium for the cathode material in Na+- battery. Soluble Prussian blue (SPB) refers the PB that is in colloidal form. In this study, we compared the x-ray diffraction patterns and magnetic properties for soluble Na-Fe-Fe PB phase of various Na-content. Various amounts of sodium citrate were introduced into the chemical mixtures in reaction for the formations of SPB. The compounds obtained with molar concentrations of 0.02, 0.08 and 0.16 M are designed as NF1, NF2 and NF3, respectively. Profile refinements of the x-ray diffraction patterns give lattice constants of the three as-prepared samples, designed as NF1, NF2 and NF3, are 10.175, 10.187 and 10.117 Å, with sodium contents of 1.35, 1.86 and 1.78, respectively. The occupancy of [Fe(CN)6] sectors decrease from 0.85 to 0.79 and increase to 0.89. The distance between the two high-spin Fe3+ ions is equal to the lattice constant, since they are located at the corner of unit cell. Separation calculations give CN spatial separation of 1.06Å, 1.16Å and 1.73Å for the three compounds. Interestingly, the CN separation of NF3 is considerably longer than the other two. Field magnetization curves reveal the saturation magnetization Ms of 109.38 and 147.82 emu/g for NF1 and NF3, respectively. Magnetic transitions were identified using the temperature dependence of the ac magnetic susceptibility to give TC of 3.72, 4.04 and 1.92 K for NF1, NF2 and NF3, respectively. The decreases in the magnetic susceptibility responses below 4K revealed in the NF1 and NF2 compounds can be associated with less [Fe(CN)6] content and the C-N separation. The UV-VIS absorption spectra reveal absorption maxima at 685, 680 to 670 nm for the NF1, NF2 and NF3 compound, respectively.

Keywords: Nanomaterial, Magnetic, XRD, Prussian Blue