A tremendous amount of research has witnessed the exploration of two-dimensional (2D) materials with intrinsic ferromagnetism and diverse physical properties. However, the low Curie temperature and deficient magnetic anisotropy hinder their practical applications in nanoscale spintronics. Based on first-principles calculations, we propose a new family of 2D ternary transition metal tellurides, CrX2Te4 (X = Al, Ga, and In), with both structural and magnetic stabilities at room temperature. Our calculations demonstrate that the 2D CrX2Te4 crystal exhibits the intrinsic 100% spin-polarized half-metallic feature with spin-up metallic and spin-down semi-conducting properties. With the remarkable magnetic moment of 4 μB per Cr atom, both 2D CrAl2Te4 and CrGa2Te4 crystals perform robust ferromagnetism with the out-of-plane magnetic anisotropy, while the 2D CrIn2Te4 crystal prefers the in-plane easy magnetization axis. The Monte Carlo simulation based on the 2D Heisenberg model shows that the critical Curie temperatures of the 2D CrAl2Te4, CrGa2Te4, and CrIn2Te4 crystals could reach 466, 431, and 536 K, respectively. Moreover, the magnetic exchange strength and magnetic anisotropy could be further enhanced by the in-plane biaxial strain. The novel electronic and magnetic features promote 2D CrX2Te4 (X = Al, Ga, and In) crystals as a new family of two-dimensional intrinsic ferromagnetic materials for next-generation advanced spintronics.

中文翻译：

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二维三元过渡金属碲化物 CrX2Te4（X = Al、Ga 和 In）中的本征室温铁磁性

大量的研究见证了对具有内在铁磁性和多种物理性质的二维（2D）材料的探索。然而，居里温度低和磁各向异性不足阻碍了它们在纳米自旋电子学中的实际应用。基于第一性原理计算，我们提出了一个新的二维三元过渡金属碲化物族，CrX2Te4（X = Al、Ga和In），在室温下具有结构和磁稳定性。我们的计算表明，2D CrX2Te4 晶体表现出固有的 100% 自旋极化半金属特征，具有自旋向上金属和自旋向下半导体特性。凭借每个 Cr 原子 4 μB 的显着磁矩，2D CrAl2Te4 和 CrGa2Te4 晶体均表现出具有面外磁各向异性的强大铁磁性，而 2D CrIn2Te4 晶体则更倾向于面内易磁化轴。基于二维海森堡模型的蒙特卡罗模拟表明，二维CrAl2Te4、CrGa2Te4和CrIn2Te4晶体的临界居里温度分别可达466、431和536 K。此外，面内双轴应变可以进一步增强磁交换强度和磁各向异性。新颖的电子和磁性特性促使 2D CrX2Te4（X = Al、Ga 和 In）晶体成为新一代先进自旋电子学的二维本征铁磁材料的新系列。