Preparing Small-Sized Functional Materials By Using Heteropolyacid

Regarding different polyoxometalates as raw materials, the different morphologicalpolyoxometalates (POMs) and multi-oxides were prepared by electrospinning andcalcinations. These factors that morphologies of materials were discussed and researched, inthe same time, the corresponding magnetic properties also discussed.1. Using electrospinning and calcinations technique, the ultra-mats were prepared,including α₂-K₈P₂W₁₇MnO₆₁,α₂-K₈P₂W₁₇FeO₆₁, α₂-K₈P₂W₁₇CuO₆₁, and micro-rods ofα-K₈P₂W₁₇NbO₆₂ and micro-particles of α-K₉P₂W₁₅Nb₃O₆₂ also prepared successfully.2. Data of FT-IR spectrums and X-ray diffraction indicated that the calcined micro-sizePOMs kept in good agreement with original compounds. Scanning electron microscopy(SEM) showed that the obtained pure POMs were smaller than the micro-mats ofPVA/POMs. The results why different morphologies of POMs were arising from that wereexplored and researched, either.3. The magnetic properties of micro-structured α₂-K₈P₂W₁₇CoO₆₁ andα₂-K₈P₂W₁₇NiO₆₁ were measured by a Quantum Design MPMS-5 SQUID magnetometer inthe temperature range300 K to 2 K. The magnetism of small sized POMs was different fromthe bulk. The ferromagnetic behavior of POMs was remarkable at high temperature range,however, the antiferromagnetism was indicated at low temperature. We provide rationalexplanations for the different magnetism between micro-fibers and bulk POMs.4. Using electrospinning and calcinations technique, different compound oxides wereprepared, when the PVA/POMs were regarded as raw materials. These differentmorphologies and crystalline phase of compound oxides were testified by X-ray diffractionand SEM morphologies, respectively.5. Using electrospinning and calcinations technique, different compound oxides wereprepared, when the PVA/POMs and common inorganic compounds were regarded as rawmaterials, respectively. When the POMs were regarded as raw materials, the magneticsusceptibilities of obtained compound oxides were bhigher than another compounds, and themagntic properties shown the ferromagnetic couples. However, the magnetic susceptibilityof common inorganic compound oxides was readily to the other disparamagneticcompounds and the environments, and indicated antiferromagnetic couples.