M-type hexagonal ferrite powder was prepared by the molten salt flux method calcined at a relatively low temperature (850 °C) with a product yield of 99.87%. The synthesized sample was then milled for 3 h by high-energy ball milling in toluene suspension to obtain ultrafine nanoparticles. The structural, morphological, and magnetic properties of the particles were investigated to observe the effect of milling on the molten salt synthesized powder. The analyses reveal the presence of barium hexaferrite (BaFe12O19) as the main phase with less impurities. Average crystallite size, determined by X-ray diffraction (XRD), decreased from 81 ± 20 nm to 52 ± 5 nm after ball milling. The Fourier transform infrared (FTIR) spectra ensure the tetrahedral and octahedral positions in barium hexaferrite structure with an increase in the intensity of absorption bands after milling. The electron paramagnetic resonance (EPR) signal shows a broad line that demonstrates a decrease in the amplitude of the milled sample. Furthermore, remanence measured by vibrating sample magnetometer (VSM) increases from 8.5 to 25 emu/g. A 72% increase in coercivity and 84% increase in magnetic saturation is observed for the milled samples compared to that of pure BaFe12O19 (unmilled). The variations of the magnetic properties are thus attributed to the reduction in crystalline size and lattice parameters after milling.

中文翻译：

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高能球磨对熔盐合成六铁酸钡粉体的影响

M型六方铁氧体粉体采用熔盐熔剂法在较低温度（850℃）下煅烧制备，产品收率为99.87%。然后将合成的样品在甲苯悬浮液中通过高能球磨研磨 3 小时以获得超细纳米颗粒。研究了颗粒的结构、形态和磁性，以观察研磨对熔盐合成粉末的影响。分析表明，六铁酸钡 (BaFe12O19) 作为主要相的存在，杂质较少。通过 X 射线衍射 (XRD) 测定的平均微晶尺寸在球磨后从 81 ± 20 nm 减小到 52 ± 5 nm。傅里叶变换红外 (FTIR) 光谱确保六铁氧体钡结构中的四面体和八面体位置，研磨后吸收带强度增加。电子顺磁共振 (EPR) 信号显示一条宽线，表明研磨样品的振幅降低。此外，通过振动样品磁强计 (VSM) 测量的剩磁从 8.5 增加到 25 emu/g。与纯 BaFe12O19（未研磨）相比，研磨后的样品矫顽力增加了 72%，磁饱和度增加了 84%。因此，磁性能的变化归因于研磨后晶体尺寸和晶格参数的降低。电子顺磁共振 (EPR) 信号显示一条宽线，表明研磨样品的振幅降低。此外，通过振动样品磁强计 (VSM) 测量的剩磁从 8.5 增加到 25 emu/g。与纯 BaFe12O19（未研磨）相比，研磨后的样品矫顽力增加了 72%，磁饱和度增加了 84%。因此，磁性能的变化归因于研磨后晶体尺寸和晶格参数的降低。电子顺磁共振 (EPR) 信号显示一条宽线，表明研磨样品的振幅降低。此外，通过振动样品磁强计 (VSM) 测量的剩磁从 8.5 增加到 25 emu/g。与纯 BaFe12O19（未研磨）相比，研磨后的样品矫顽力增加了 72%，磁饱和度增加了 84%。因此，磁性能的变化归因于研磨后晶体尺寸和晶格参数的降低。