Ab initio calculations are performed to investigate theoretically the structural stability, electronic, magnetic, and elastic properties of dilute magnetic semiconductors Ca_0.75TM_0.25S (TM = Mn, Co, and Ni). These materials crystallize in the ferromagnetic rock-salt phase and are made by doping the CaS binary semiconductor with transition metals at a fixed concentration. Calculations are performed using the full-potential linearized augmented plane wave method, plus the local orbital method (FP-LAPW+lo). The correlation exchanges potential and the structural properties are calculated using the generalized gradient approximation proposed by Perdew-Burk-Ernzerhof (PBE-GGA) and the electronic and magnetic properties are calculated using the Becke and Johnson modified local density approximation (mBJ–LDA). The comparison of curves giving energy as a function of volume in the fundamental state of the compounds in the ferromagnetic (FM), antiferromagnetic (AFM), and paramagnetic (PM) phases presented that the compounds are stable in the ferromagnetic phase. Analysis of the electronic properties showed that Ca_0.75Mn_0.25S, Ca_0.75Co_0.25S, and Ca_0.75Ni_0.25S are all ferromagnetic semiconductors. Various parameters like spin-exchange splittingΔ_x(d), crystal field energyΔE_Crystal, and exchange constants N₀αand N₀β have also confirmed a stable ferromagnetic state. The magnetic study revealed a strong contribution to the value of the total magnetic moment of the compounds, with low contributions coming from the non-magnetic atoms Ca and S. The Curie temperature values, calculated by the mean-field approximation, are 240.78 K, 228.79 K, and 150.31 K in the compounds containing Mn, Co, and Ni, respectively. The study of the mechanical properties of the host semiconductors CaS doped with transition metals, Mn, Co, and Ni, carried out at zero pressure has shown that all compounds are brittle and mechanically stable.

从头算开始进行计算以从理论上研究稀磁半导体Ca _0.75 TM _0.25的结构稳定性，电子，磁性和弹性特性S（TM = Mn，Co和Ni）。这些材料在铁磁岩盐相中结晶，并通过在CaS二元半导体中掺入固定浓度的过渡金属制成。使用全势线性化增强平面波方法以及局部轨道方法（FP-LAPW + lo）进行计算。使用Perdew-Burk-Ernzerhof（PBE-GGA）提出的广义梯度近似来计算相关交换势和结构特性，并使用Becke and Johnson修正的局部密度近似（mBJ-LDA）计算电子和磁性。在铁磁（FM），反铁磁（AFM）中，化合物基本状态下能量随体积变化的曲线比较，顺磁性（PM）相表明该化合物在铁磁性相中稳定。电子性能分析表明，Ca_0.75 Mn _0.25 S，Ca _0.75 Co _0.25 S和Ca _0.75 Ni _0.25 S都是铁磁半导体。各种参数如旋交换分裂Δ _X（d），晶体场能量ΔE_晶体，和交换常数Ñ ₀ α和Ñ ₀ β也证实了稳定的铁磁状态。磁性研究表明，化合物的总磁矩值有很大贡献，而非磁性原子Ca和S贡献很小。通过平均场近似计算得出的居里温度值为240.78 K，分别含有Mn，Co和Ni的化合物中的228.79 K和150.31K。在零压力下对掺有过渡金属Mn，Co和Ni的主体半导体CaS的机械性能进行的研究表明，所有化合物都是易碎的，并且机械稳定。