Pawlik Katarzyna, Pawlik Piotr, Wysłocki Jerzy J, Kaszuwara Waldemar
Department of Physics, Faculty of Production Engineering and Materials Technology, Częstochowa University of Technology, Al. Armii Krajowej 19, 42-200 Częstochowa, Poland.
Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Wołoska 141, 02-507 Warsaw, Poland.
Materials (Basel). 2020 Mar 26;13(7):1515. doi: 10.3390/ma13071515.
In the present study, the phase constitution, microstructure and magnetic properties of the nanocrystalline magnets, derived from fully amorphous or partially crystalline samples by annealing, were analyzed and compared. The melt-spun ribbons (with a thickness of ~30 µm) and suction-cast 0.5 mm and 1 mm thick plates of the PrFeCoZrNbB alloy were soft magnetic in the as-cast state. In order to modify their magnetic properties, the annealing process was carried out at various temperatures from 923K to 1033K for 5 min. The Rietveld refinement of X-ray diffraction patterns combined with the partial or no known crystal structures (PONKCS) method allowed one to quantify the component phases and calculate their crystalline grain sizes. It was shown that the volume fraction of constituent phases and their crystallite sizes for the samples annealed at a particular temperature, dependent on the rapid solidification conditions, and thus a presence or absence of the crystallization nuclei in the as-cast state. Additionally, a thermomagnetic analysis was used as a complementary method to confirm the phase constitution. The hysteresis loops have shown that most of the samples exhibit a remanence enhancement typical for the soft/hard magnetic nanocomposite. Moreover, for the plates annealed at the lowest temperatures, the highest coercivities up to ~1150 kA/m were measured.
在本研究中，对通过退火从完全非晶态或部分晶态样品获得的纳米晶磁体的相组成、微观结构和磁性能进行了分析和比较。熔体纺丝带（厚度约为30μm）以及PrFeCoZrNbB合金的0.5mm和1mm厚的吸铸板在铸态下是软磁的。为了改变它们的磁性能，在923K至1033K的不同温度下进行5分钟的退火处理。结合部分或无已知晶体结构（PONKCS）方法的X射线衍射图谱的Rietveld精修，能够对组成相进行定量并计算其晶粒尺寸。结果表明，在特定温度下退火的样品，其组成相的体积分数和微晶尺寸取决于快速凝固条件，进而取决于铸态下是否存在结晶核。此外，热磁分析被用作补充方法来确认相组成。磁滞回线表明，大多数样品表现出软/硬磁纳米复合材料典型的剩磁增强。而且，对于在最低温度下退火的板材，测量到高达约1150kA/m的最高矫顽力。
