MnFeP(As, Ge, Si) series compounds are three kinds of MnFe-based magnetocaloric materials, which have giant magnetocaloric effect. In this work, the experimental characteristic curves of new style Mn-Fe-P-Si materials, numbered as 1: Mn_1.32Fe_0.67P_0.52Si_0.49, 2: Mn_1.37Fe_0.63P_0.5Si_0.5, and 3: Mn_1.35Fe_0.66P_0.5Si_0.5 are presented. Based on the experimental data of these component materials and thermodynamic analysis method, a novel composite material is put forward. The optimal molar mass ratios of the composite material are obtained and they are 0.22, 0.33, 0.45, respectively. A regenerative Brayton refrigeration cycle employing the optimal composite material with thermal hysteresis as the working medium is built. By numerical calculation, the influences of thermal hysteresis on the main thermodynamic quantities are evaluated. The results show that the thermal hysteresis of the working medium results in a decrease of 13.6%, 14.6%, 18.8%, and 16.1% of the cooling quantity, net cooling quantity, optimally working temperature range, and coefficient of performance, respectively. These conclusions are beneficial to the optimal parameter design and performance improvement of active magnetic refrigerators.

MnFeP(As,Ge,Si)系列化合物是三种MnFe基磁热材料，具有巨磁热效应。在这项工作中，新型Mn-Fe-P-Si材料的实验特性曲线，编号为1：Mn _1.32 Fe _0.67 P _0.52 Si _0.49、2：Mn _1.37 Fe _0.63 P _0.5 Si _0.5和3：Mn _1.35 Fe _0.66磷_0.5硅_0.5被提出。基于这些组分材料的实验数据和热力学分析方法，提出了一种新型复合材料。得到了复合材料的最佳摩尔质量比，分别为0.22、0.33、0.45。构建了以具有热滞效应的最优复合材料为工质的蓄热式布雷顿制冷循环。通过数值计算，评价了热滞对主要热力学量的影响。结果表明，工质的热滞导致冷却量、净冷却量、最佳工作温度范围和性能系数分别下降13.6%、14.6%、18.8%和16.1%。