Azis Raba'ah Syahidah, Che Muda Nor Nadhirah, Hassan Jumiah, Shaari Abdul Halim, Ibrahim Idza Riati, Mustaffa Muhammad Syazwan, Sulaiman Sakinah, Matori Khamirul Amin, Fen Yap Wing
Department of Physics, Faculty of Science, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA), University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Materials (Basel). 2018 Nov 6;11(11):2190. doi: 10.3390/ma11112190.
This paper investigates the effect of the ratio of ammonium nitrate (AN) on the structural, microstructural, magnetic, and alternating current (AC) conductivity properties of barium hexaferrite (BaFeO). The BaFeO were prepared by using the salt melt method. The samples were synthesized using different powder-to-salt weight ratio variations (1:3, 1:4, 1:5, 1:6 and 1:7) of BaCO₃ + Fe₂O₃ and ammonium nitrate salt. The NH₄NO₃ was melted on a hot plate at 170 °C. A mixture of BaCO₃ and Fe₂O₃ were added into the NH₄NO₃ melt solution and stirred for several hours using a magnetic stirrer under a controlled temperature of 170 °C. The heating temperature was then increased up to 260 °C for 24 hr to produce an ash powder. The x-ray diffraction (XRD) results show the intense peak of BaFeO for all the samples and the presence of a small amount of the impurity Fe₂O₃ in the samples, at a ratio of 1:5 and 1:6. From the Fourier transform infra-red (FTIR) spectra, the band appears at 542.71 cm - 1 and 432.48 cm - 1 , which corresponding to metal⁻oxygen bending and the vibration of the octahedral sites of BaFeO. The field emission scanning electron microscope (FESEM) images show that the grains of the samples appear to stick each other and agglomerate at different masses throughout the image with the grain size 5.26, 5.88, 6.14, 6.22, and 6.18 µm for the ratios 1:3, 1:4, 1:5, 1:6, and 1:7 respectively. From the vibrating sample magnetometer (VSM) analysis, the magnetic properties of the sample ratio at 1:3 show the highest value of coercivity of 1317 Oe, a saturation magnetization of 91 emu/g, and a remnant of 44 emu/g, respectively. As the temperature rises, the AC conductivity is increases with an increase in frequency.
本文研究了硝酸铵（AN）比例对六方铁酸钡（BaFeO）的结构、微观结构、磁性和交流电（AC）导电性能的影响。采用盐熔法制备了BaFeO。使用BaCO₃ + Fe₂O₃与硝酸铵盐不同的粉末与盐重量比变化（1:3、1:4、1:5、1:6和1:7）合成样品。NH₄NO₃在170°C的热板上熔化。将BaCO₃和Fe₂O₃的混合物加入到NH₄NO₃熔体溶液中，并在170°C的控制温度下使用磁力搅拌器搅拌数小时。然后将加热温度升至260°C并保持24小时以产生灰粉。X射线衍射（XRD）结果表明，所有样品中BaFeO的峰均很强烈，并且在比例为1:5和1:6的样品中存在少量杂质Fe₂O₃。从傅里叶变换红外（FTIR）光谱来看，在542.71 cm⁻¹和432.48 cm⁻¹处出现谱带，分别对应于金属 - 氧弯曲以及BaFeO八面体位置的振动。场发射扫描电子显微镜（FESEM）图像显示，样品的晶粒似乎相互粘连并在整个图像中以不同质量团聚，对于比例1:3、1:4、1:5、1:6和1:7，晶粒尺寸分别为5.26、5.88、6.14、6.22和6.18 µm。通过振动样品磁强计（VSM）分析，比例为1:3的样品的磁性显示矫顽力最高值为1317 Oe，饱和磁化强度为91 emu/g，剩余磁化强度为44 emu/g。随着温度升高，交流电导率随频率增加而增大。
