Boutahar A, Moubah R, Hlil E K, Lassri H, Lorenzo E
LabSIPE, Ecole Nationale des Sciences Appliquées, Université Chouaib Doukkali d'El Jadida, El Jadida, Plateau, 24002, Morocco.
LPMMAT, Université Hassan II-Casablanca, Faculté des Sciences Ain Chock, BP, 5366, Mâarif-Casablanca, Morocco.
Sci Rep. 2017 Oct 24;7(1):13904. doi: 10.1038/s41598-017-14279-y.
Giant magnetocaloric materials are highly promising for technological applications in magnetic refrigeration. Although giant magnetocaloric effects were discovered in first-order magnetic transition materials, it is accompanied by some non-desirable drawbacks, such as important hysteretic phenomena, irreversibility of the effect, or poor mechanical stability, which limits their use in applications. Here, we report the discovery of a giant magnetocaloric effect in commercialized HoO oxide at low temperature (around 2 K) without hysteresis losses. HoO is found to exhibit a second-order antiferromagnetic transition with a Néel temperature of 2 K. At an applied magnetic field change of 5 T and below 3.5 K, the maximum value of magnetic entropy change [Formula: see text], the refrigerant capacity (RC) were found to be 31.9 J.K.kg and 180 J.K, respectively.
巨型磁热材料在磁制冷技术应用方面极具前景。尽管在一级磁转变材料中发现了巨型磁热效应，但它伴随着一些不理想的缺点，如显著的磁滞现象、效应的不可逆性或较差的机械稳定性，这限制了它们在应用中的使用。在此，我们报告了在商业化的氧化钬中低温（约2K）下发现的无磁滞损耗的巨型磁热效应。发现氧化钬表现出奈尔温度为2K的二级反铁磁转变。在5T的外磁场变化且温度低于3.5K时，磁熵变[公式：见原文]的最大值、制冷量（RC）分别为31.9J·K⁻¹·kg⁻¹和180J·K⁻¹。
