By using the Ab initio and Monte Carlo calculations, we have studied the magnetism of the crystalline La_0.75Sr_0.25MnO₃ perovskite. The ferromagnetic phase of La_0.75Sr_0.25MnO₃ is half-metallic, which is important in the relation to the colossal magnetoresistance properties of this compound. The total magnetic moment and the exchange couplings deduced from ab initio calculations lead, by using Monte Carlo simulations, to a quantitative agreement with the experimental transition temperatures. The maximum magnetic entropy change and the specific heat are found to be 9.23 J K⁻¹ kg ⁻¹ and 191 J mol ${}^{-}$1 K⁻¹, respectively for $H=6$ T. Our results suggest that this material a promising candidate for magnetic refrigeration application near to room temperature at moderate fields.

通过使用从头算和蒙特卡洛计算，我们研究了晶体La _0.75 Sr _0.25 MnO ₃钙钛矿的磁性。La _0.75 Sr _0.25 MnO ₃的铁磁相是半金属的，这对于与该化合物的巨大磁阻性质有关很重要。通过使用蒙特卡洛模拟，从头算计算得出的总磁矩和交换耦合导致与实验转变温度的定量一致。发现最大磁熵变和比热为9.23 J K ^-1  kg ^-1和191 J mol${}^{-}$1 K ^-1分别用于$H=6$ T.我们的结果表明，这种材料是在中等温度下接近室温的磁制冷应用的有前途的候选者。