Si添加对GdCoAl系合金非晶形成能力和磁热效应的影响

Abstract

利用铜模吸铸法制备了Gd-Co-Al-Si非晶合金。利用X射线衍射(XRD)、差示扫描量热法(DSC)和物性测量装置(PPMS)研究了其结构、热稳定性和磁热效应。结果显示：微量Si元素的加入可以显著提高合金的非晶形成能力和热稳定性。合金同时具有良好的磁热效应，具有9.2 J/kgK的最大磁熵变值(ΔSm)和800 J/kg磁致冷能力值(RC)。该研究表明GdCoAlSi合金可作为一种良好的磁致冷工质工作在液氮温区的附近。 In this work, the Gd-Co-Al-Si bulk glassy alloys were synthesized by suck-cast method. The structure, thermal stability and magnetism of the alloys were taken by the X-ray diffraction (XRD), differential scanning calorimetry (DSC) and physical property measurement system (ppms) analysis. It is found that micro content of Si addition can extend the supercooled liquid region (ΔTx). As the result, the glass-forming ability (GFA) of the Gd-based alloys dramatically increased. The alloys also exhibit large magnetocaloric effect (MCE), ie, having the magnetic entropy change (ΔSm) of 9.2 J kg-1 K-1 and the regrigerant capacity (RC) of 800 J kg-1.