分类: 医学、药学 >> 临床医学 提交时间: 2023-11-10 合作期刊: 《中国全科医学》
摘要: none
分类: 材料科学 >> 纳米科学和纳米技术 提交时间: 2017-05-09
摘要: The Gd-Fe-Al amorphous/nanocrystalline composites were successfully designed and obtained with both high Curie temperature (Tc) and large magnetic entropy change (∆SM). The Tc can be tuned from 172 to 280 K and refrigeration capacity (RC) has a value between 690 and 867 J/kg under a eld change of 0–5 T by changing the Gd contents and the formation of Gd nanocrystallites. And, ∆SM in Gd-Fe-Al amorphous/nanocrystalline composites reached a value of 7.2 J kg−1 K−1 under a eld change of 0–5 T. The high RC in Gd-Fe-Al system were ascribed to the widening full width at half maximum (δFWHM) up to 240 K of the magnetic entropy change (∆SMmax) peak because of the combination contribution of amorphous matrix and the precipitated Gd-riched nanocrystalline. Our research would shed light on how to design attractive candidates for magnetic refrigeration materials with high perfor- manceatnearroomtemperature
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: This study investigates the composition dependence of magnetic structures of (Fe1−xMnx)Pt using first- principles method. A series of possible magnetic configurations are considered in the calculation to compare the relative stabilities after structural optimization, based on which, together with the com- parison between theoretical and experimental magnetic properties, the results largely support the ex- perimental finding in powders. The experimentally found stability of ferrimagnetic state in films with a wide composition range of x ≤ 0.5 is not fully supported by this study. The composition-dependent magnetic structures are discussed according to the exchange interactions.