Tsay Chien-Yie, Chiu Yi-Chun, Lei Chien-Ming
Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan.
Department of Chemical and Materials Engineering, Chinese Culture University, Taipei 11114, Taiwan.
Materials (Basel). 2018 Nov 14;11(11):2274. doi: 10.3390/ma11112274.
Three kinds of magnesium-based spinel nanoferrites with the chemical formulas of MgFe₂O₄ (Mg ferrite), MgMnFe₂O₄ (Mg-Mn ferrite), and MgMnInFeO₄ (Mg-Mn-In ferrite) were synthesized by hydrothermal route. We report the composition-dependent magnetic parameters and microwave properties of Mg-based ferrite nanoparticles. XRD results revealed that the Mg-based ferrite nanoparticles exhibited a cubic spinel structure and had an average nanocrystallite size in the range of 5.8⁻2.6 nm. Raman spectroscopy analysis confirmed the formation of cubic-spinel phase Mg-based nanoferrites. The room-temperature magnetization measurements indicated that the Mg ferrite nanoparticles had superparamagnetic behavior; whereas the Mg-Mn and Mg-Mn-In ferrite nanoparticles exhibited a paramagnetic nature. The microwave properties of obtained ferrite nanoparticles were studied by alternating current (AC) magnetic susceptibility measurement and electron paramagnetic resonance (EPR) spectroscopy. It was found that the un-substituted Mg ferrite sample exhibited microwave characteristics better than those of the Mn substituted and Mn-In co-substituted Mg ferrite samples.
通过水热法合成了化学式为MgFe₂O₄（镁铁氧体）、MgMnFe₂O₄（镁锰铁氧体）和MgMnInFeO₄（镁锰铟铁氧体）的三种镁基尖晶石纳米铁氧体。我们报道了镁基铁氧体纳米颗粒的成分依赖性磁参数和微波特性。X射线衍射结果表明，镁基铁氧体纳米颗粒呈现立方尖晶石结构，平均纳米晶粒尺寸在5.8⁻2.6纳米范围内。拉曼光谱分析证实了立方尖晶石相镁基纳米铁氧体的形成。室温磁化测量表明，镁铁氧体纳米颗粒具有超顺磁行为；而镁锰和镁锰铟铁氧体纳米颗粒表现出顺磁性质。通过交流（AC）磁化率测量和电子顺磁共振（EPR）光谱研究了所得铁氧体纳米颗粒的微波特性。发现未取代的镁铁氧体样品表现出比锰取代和锰铟共取代的镁铁氧体样品更好的微波特性。
