CrK(SO_(4))_(2)·12H_(2)O晶体的生长及其磁制冷性能  

Growth and Characterization of CrK(SO_(4))_(2)·12H_(2)O Crystals Used in Magnetic Adiabatic Refrigerator

作　　者：陈语葳 刘萍 刘旺 王昌 戴巍[1] 沈俊[1] 张国春[1,2] 涂衡 CHEN Yuwei;LIU Ping;LIU Wang;WANG Chang;DAI Wei;SHEN Jun;ZHANG Guochun;TU Heng(Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院理化技术研究所,北京100190 [2]中国科学院大学材料科学与光电工程中心,北京100049

出　　处：《硅酸盐学报》2022年第12期3270-3275,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(52088101,51925605,51972314)。

摘　　要：顺磁盐在超低温制冷方面具有绝对优势,且在极低温度下使用时往往是其水合盐类晶体,对水合盐类磁制冷材料的探索意义重大。本工作采用缓慢降温法生长出尺寸为32 mm×32 mm×20 mm的CrK(SO_(4))_(2)·12H_(2)O(CPA)单晶,分析了生长条件与晶体形貌之间的相互关系,研究了CPA的热稳定性和磁热性能。结果表明,CPA在温度为2 K、外加磁场强度为7 T条件下,表现出大的磁热效应,磁熵变值达到29.75 J·kg^(-1)·K^(-1)。在密集排布铜线的密封容器中生长CPA晶体,并将其用于2级单冲程绝热去磁制冷系统中,空载条件下制冷温度达到90 m K。Paramagnetic salts perform satisfactorily in cryogenic refrigeration,and hydrated salt crystals are usually used as refrigerated materials at a rather low temperature.In this paper,a chromium potassium alum CrK(SO_(4))_(2)·12H_(2)O(CPA)single crystal with the size of 32 mm×32 mm×20 mm was grown by a slow cooling method.The relationship between the growth condition and crystal morphology was analyzed,and the thermal behavior,infrared spectrum,and magnetic performance of CPA crystal were also investigated.The results reveal that the CPA crystal exhibits a magnetocaloric effect up to 29.75 J·kg^(-1)·K^(-1)in an applied magnetic field of 7 T at 2 K.A salt pill made by growing the CPA crystals on an array of copper wires in a sealed container was used in a two-stage single-shot adiabatic demagnetization refrigerator,obtaining a no-load temperature of 90 m K.

关 键 词：晶体生长 晶体形貌 顺磁盐材料 磁热效应 

分 类 号：G312[文化科学]