Magnetocaloric Effect in AlFe2B2: Toward Magnetic Refrigerants from Earth-Abundant Elements
Magnetocaloric Effect in AlFe2B2: Toward Magnetic Refrigerants from Earth-Abundant Elements
复制标题
DOI：
10.1021/ja404107p
复制
发表时间：
2013-06-26
影响因子：
15
通讯作者：
Shatruk, Michael
中科院分区：
文献类型：
--
作者：
Tan, Xiaoyan;Chai, Ping;Shatruk, Michael
AlFe2B2 通过两种替代合成路线制备，即电弧熔炼和 Ga 熔剂合成。在层状晶体结构中，无限的 B 原子链通过 Fe 原子连接成二维 [Fe2B2] 板，与 Al 原子层交替。正如电子能带结构理论分析所预期的那样，该化合物表现出巡回铁磁性，有序温度为 307 K。磁热效应 (MCE) 测量结果显示，2 T 时的等温熵变化为 4.1 J kg(-1) K-1，5 T 时为 77 J kg(-1) K-1。这些是任何金属在室温附近观察到的最大值。 硼化物以及 122 层状结构家族中的任何磁性材料。重要的是，AlFe2B2 代表了一种由地球丰富的良性反应物制备的轻质材料的罕见案例，它表现出大量的 MCE，同时不含任何稀土元素。
AlFe2B2 was prepared by two alternative synthetic routes, arc melting and synthesis from Ga flux. In the layered crystal structure, infinite chains of B atoms are connected by Fe atoms into two-dimensional [Fe2B2] slabs that alternate with layers of Al atoms. As expected from the theoretical analysis of electronic band structure, the compound exhibits itinerant ferromagnetism, with the ordering temperature of 307 K. The measurement of magnetocaloric effect (MCE) as a function of applied magnetic field reveals isothermal entropy changes of 4.1 J kg(-1) K-1 at 2 T and 77 J kg(-1) K-1 at 5 T. These are the largest values observed near room temperature for any metal boride and for any magnetic material of the vast 122 family of layered structures. Importantly, AlFe2B2 represents a rare case of a lightweight material prepared from earth abundant, benign reactants which exhibits a substantial MCE while not containing any rare-earth elements.