Carbon combustion synthesis of Janus-like particles of magnetoelectric cobalt ferrite and barium titanate
Carbon combustion synthesis of Janus-like particles of magnetoelectric cobalt ferrite and barium titanate
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DOI：
10.1016/j.ceramint.2020.10.123
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
C. D. Leo;G. C. Dannangoda-;M. Hobosyan;Jacob T. Held;F. S. Samghabadi;M. Khodadadi;D. Litvinov;K. Mkhoyan;K. Martirosyan
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文献类型：
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作者：
C. D. Leo;G. C. Dannangoda-;M. Hobosyan;Jacob T. Held;F. S. Samghabadi;M. Khodadadi;D. Litvinov;K. Mkhoyan;K. Martirosyan
采用碳燃烧合成氧化物的方法，快速、节能地制备了钴铁氧体和钛酸钡的多铁性复合材料，形成了类Janus颗粒基体结构。平均尺寸为5 nm、比表面积为110 m2/g的碳纳米颗粒的放热氧化产生自传播热波，峰值温度高达1000 °C。热锋通过固体反应物（磁性-CoFe 2 O 4和铁电-BaTiO 3）的混合物快速传播，并导致磁电相的局部热点烧结以形成纳米复合结构。碳不包含在产品中，并作为气态CO2排放。X射线粉末衍射（XRD）沿着SEM和TEM分析证实了复合纳米结构中存在离散的CoFe 2 O 4和BaTiO 3相。我们估算了燃烧合成Janus状颗粒的活化能为112 ± 3.3 kJ/mol，表明钛酸钡和钴铁氧体的存在降低了碳氧化的活化能垒，促进了燃烧合成的点火过程。我们观察到合成的样品在多铁性钴铁氧体-钛酸钡陶瓷复合材料上表现出磁电耦合。
Carbon combustion synthesis of oxides was applied for quick and energy efficient production of multiferroic composite of cobalt ferrite and barium titanate to form Janus-like particles matrix structure. The exothermic oxidation of carbon nanoparticles with an average size of 5 nm and a specific surface area of 110 m2/g generates a self-propagating thermal wave with peak temperature of up to 1000 °C. The thermal front rapidly propagates through the mixture of solid reactants (magnetic- CoFe2O4and ferroelectric-BaTiO3) and results in localized hot-spot sintering of magneto-electric phases to form a nanocomposite structure. Carbon is not incorporated in the product and is emitted as a gaseous CO2. Existence of discrete CoFe2O4and BaTiO3phases in the composites nanostructures was confirmed using X-ray powder diffraction along with SEM and TEM analysis. We estimated the activation energy for the combustion synthesis of Janus-like particles to be 112 ± 3.3 kJ/mol, indicating that the barium titanate and cobalt ferrite presence decrease the activation energy barrier of carbon oxidation and facilitate the ignition process of the combustion synthesis. We observe that the as-synthesized samples show magnetoelectric coupling on multiferroic cobalt ferrite–barium titanate ceramic composites.