Zeleňáková A, Hrubovčák P, Berkutova A, Šofranko O, Kučerka N, Ivankov O, Kuklin A, Girman V, Zeleňák V
Institute of Physics, P.J. Šafárik University, Park Angelinum 9, 04001, Košice, Slovakia.
Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Russia, 141980.
Sci Rep. 2022 Feb 10;12(1):2282. doi: 10.1038/s41598-022-06132-8.
The series of advanced nanocomposites consisting of GdO nanoparticles (NPs) embedded into periodic porous SiO matrix have been investigated with respect to their structural and magnetocaloric properties. By means of small angle neutron scattering and transmission electron microscopy, regular nanopores organized in the cubic or hexagonal superlattice have been documented. The pores are occupied by the NPs of progressive concentration within the nanocomposite series. All of the examined systems have exhibited extraordinarily high values of magnetic entropy change (up to 70 J kg K) at low temperatures with the absence of thermal hysteresis, indicating their perspective utilization in cryogenic refrigeration. Profound analysis of magnetic entropy change data via scaling laws has been applied to the nanocomposite materials for the very first time. With the aid of scaling analysis, conclusions on magnetic properties and phase transition type have been made, even for the conditions unavailable in the laboratory.
对由嵌入周期性多孔SiO基体中的GdO纳米颗粒（NPs）组成的一系列先进纳米复合材料的结构和磁热性能进行了研究。通过小角中子散射和透射电子显微镜，记录了以立方或六方超晶格形式排列的规则纳米孔。在纳米复合材料系列中，这些孔被浓度逐渐增加的NPs占据。所有研究的系统在低温下都表现出极高的磁熵变值（高达70 J kg K），且没有热滞现象，这表明它们在低温制冷方面具有应用前景。首次通过标度律对纳米复合材料的磁熵变数据进行了深入分析。借助标度分析，即使在实验室无法实现的条件下，也能对磁性能和相变类型得出结论。
