0.75Ce0.25Fe11.5-xAl0.2Si1.3Snx（x=0，0.05，0.1，0.2）的磁熱效應(yīng)和相變性質(zhì)。X射線衍射結(jié)果表明，隨著Sn摻雜濃度的增加，主相1:13相減少，α-Fe和LaFeSi相增加。引入密度泛函理論，結(jié)合實(shí)驗(yàn)結(jié)果得出，增加Sn摻雜濃度能夠增大晶格常數(shù)，并增強(qiáng)相鄰原子之間的交換相互作用，從而提高居里溫度。當(dāng)磁場變化為2 T時(shí)，體系中最大磁熵變?yōu)?3.59 J·kg-1·K-1，其相對制冷能力為154 J/kg，具有成為磁制冷材料的潛力。通過Banerjee準(zhǔn)則和等溫熵變的場相關(guān)指數(shù)n確定當(dāng)Sn摻雜濃度為0.05%（質(zhì)量分?jǐn)?shù)）時(shí)，合金由一級相變轉(zhuǎn)變?yōu)槎壪嘧?。合金的相變行為對Sn含量非常敏感，可以通過調(diào)節(jié)Sn摻雜濃度，實(shí)現(xiàn)多級串聯(lián)制冷。;The magnetocaloric effect and phase transition properties of La0.75Ce0.25Fe11.5-xAl0.2Si1.3Snx (x=0, 0.05, 0.1, 0.2, wt%) alloys were investigated. X-ray diffraction results show that with increasing the Sn doping content, the content of 1:13 main phase is decreased, and the content of α-Fe and LaFeSi phases is increased. By combining the density functional theory with experimental results, it is found that increasing the Sn doping content can increase the lattice constant and enhance the exchange interactions between adjacent atoms, thereby increasing the Curie temperature. When the magnetic field is 2 T, the maximum magnetic entropy change in the system is 13.59 J·kg-1·K-1 and its relative cooling power is 154 J/kg, showing great potential as magnetic refrigeration material. Based on the Banerjee criterion and the field dependence index n of isothermal entropy change, it is concluded that when the Sn doping content is 0.05wt%, the first-order phase transition changes to the second-order phase transition of the alloy. The phase transition behavior of the alloy is very sensitive to the Sn content, and multi-stage series refrigeration can be achieved by adjusting the doping content."/>