An indirect approach based on Clausius-Clapeyron equation to determine entropy change for the first-order magnetocaloric materials

作者：Xu, Kun^*; Li, Zhe; Zhang, Yuan-Lei; Jing, Chao

来源：Physics Letters, Section A: General, Atomic and Solid State Physics , 2015, 379(47-48): 3149-3154.

DOI：10.1016/j.physleta.2015.10.029

• Heusler alloy
• Magnetocaloric effect
• Clausius-Clapeyron equation
• Maxwell relation

Taking into account the phase fraction during the structural transition for the first-order magnetocaloric materials, an improved isothermal entropy change (AST) determination has been put forward based on the Clausius-Clapeyron (CC) equation. It was found that the AST value evaluated by this method is in excellent agreement with those determined from the Maxwell relation (MR) using magnetic measurements for some Heusler alloys with a weak field-induced phase transforming behavior, such as Ni-Mn-Sn Heusler alloys. In comparison with the MR based on isofield magnetization measurements (MRIF), this method is very convenient to obtain the AST derived from only few thermomagnetic curves. More importantly, it is quite superior to the MR-based method in eliminating the overestimation of AST due to the appearance of the spurious spike derived from MR employing isothermal magnetization measurements (MRIT).

• 出版日期2015-12-18
• 单位曲靖师范学院; 上海大学