【作者】 隋春红；

【导师】 龚剑；

【作者基本信息】 东北师范大学 ， 无机化学， 2006， 硕士

【摘要】 本论文采用以杂多化合物为母体,通过高压静电纺丝和程序升温焙烧的方法,制备出具有不同形貌的杂多化合物和复合型氧化物,研究了产生物质形貌的影响因素,并且对相应的磁学性质进行了探讨。1、应用静电纺丝和程序升温焙烧的方法,制备了α₂-K₈P₂W₁₇MnO₆₁,α₂-K₈P₂-W₁7FeO₆₁,α₂-K₈P₂W₁₇CuO₆₁的纤维毯以及棒状的α₂-K₇P₂W₁₇NbO₆₂和颗粒状的α-K₉P₂W₁₅Nb₃O₆₂。2、红外光谱和X-粉末衍射的结果表明,经焙烧后得到的产物仍然保持着完好的杂多酸盐结构,扫描电镜照片显示,获得了直径相对较小的纤维毯、棒及颗粒状的杂多酸盐。探讨了不同取代型过渡元素的原子和不同焙烧保温时间等条件对形貌的影响。3、对α₂-K₈P₂W₁₇CoO₆₁和α₂-K₈P₂W₁₇NiO₆₁的纤维毯进行变温磁化率的测定,两者都在高温区域内呈现铁磁性偶合,低温区域内是反铁磁性偶合。同时对纤维材料和常规杂多酸盐的磁性进行了比较,并且给予了合理的解释。4、以PVA/H₄SiW₁₂O₄₀作为母体,经过静电纺丝和程序升温焙烧的方法,制备了不同复合型氧化物。通过X-射线粉末衍射和扫描电镜照片,确定了复合氧化物的形貌和晶体结构。5、分别选取以取代型杂多酸盐和普通无机混合物为原料,纺丝焙烧后得到了一系列复合型氧化物,对磁化率进行了测试和比较。结果表明以杂多化合物为母体制备氧化物的磁化率数值较大,而且在高温区域内,两种复合型氧化物显示铁磁性偶合。更多还原

【Abstract】 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.更多还原