Lu Yani, Ma Xiangyu, Ren Jinping, Kang Jinke, Wang Yatao
Gansu Key Laboratory of Efficient Utilization of Oil and Gas Resources, College of Petroleum and Chemical Engineering, Longdong University, Qingyang 745000, China.
Shanxi Aerospace Qinghua Equipment Co., Ltd., Changzhi 046000, China.
Molecules. 2025 Apr 29;30(9):1975. doi: 10.3390/molecules30091975.
We report a method for synthesizing different phases of samarium-cobalt particles through microwave-assisted combustion combined with high-temperature reduction and diffusion, and identify the optimal temperature for forming the 1:5 phase using this approach. Initially, the samarium-to-cobalt ratio in a nitrate solution was determined. Using urea as both a reductant and fuel, samarium-cobalt oxides were synthesized via microwave-assisted combustion. The main components of the oxides were confirmed to be SmCoO and CoO. Subsequently, samarium-cobalt particles were synthesized at various diffusion temperatures. The results indicate that at 700 °C, the oxides were reduced to elemental Sm and Co. As the reduction temperature increased, the alloying of samarium and cobalt occurred, and the particle size gradually increased. At 900 °C, a pure 1:5 phase was formed, with particle sizes of approximately 800 nm, a coercivity of 35 kOe, and a maximum energy product of 14 MGOe. Based on the microwave-assisted combustion method, this study clarifies the transition temperatures of samarium-cobalt phases during the reduction and diffusion process, and further establishes the synthesis temperature for the 1:5 phase, providing new insights into the preparation and development of samarium-cobalt materials and potentially other rare earth materials.
我们报道了一种通过微波辅助燃烧结合高温还原和扩散来合成不同相的钐钴颗粒的方法，并确定了使用该方法形成1:5相的最佳温度。首先，测定了硝酸盐溶液中钐与钴的比例。以尿素作为还原剂和燃料，通过微波辅助燃烧合成了钐钴氧化物。确认氧化物的主要成分是SmCoO和CoO。随后，在不同的扩散温度下合成了钐钴颗粒。结果表明，在700℃时，氧化物被还原为元素Sm和Co。随着还原温度的升高，钐和钴发生合金化，颗粒尺寸逐渐增大。在900℃时，形成了纯的1:5相，颗粒尺寸约为800nm，矫顽力为35kOe，最大磁能积为14MGOe。基于微波辅助燃烧方法，本研究阐明了钐钴相在还原和扩散过程中的转变温度，并进一步确定了1:5相的合成温度，为钐钴材料以及潜在的其他稀土材料的制备和开发提供了新的见解。
