中文摘要：

采用基于密度泛函理论的第一性原理,系统研究了Heusler合金Fe2CuGa的结构、磁性、弹性性能和电子性质。计算结果表明：立方相的基态结构是铁磁态的Hg2CuTi结构。立方到四方的相变几乎是体积不变的,这是形状记忆合金的特性。奥氏体和马氏体的磁矩分别是4.48和4.56μB/f.u.。另外,预测了Fe2CuGa的弹性系数。Fe2CuGa的立方结构在力学上是不稳定的而四方结构是稳定的。根据体模量和剪切模量的比值,发现Fe2CuGa在本质上是可延展的。利用态密度的方法解释了Fe2CuGa马氏体相变的来源。

英文摘要：

In terms of its structure and physical （magnetic, elastic and electronic） properties, the Heusler alloy Fe2CuGa was investigated by the first principles calculations based on density functional theory. The structural optimization indicates that the equilibrium structure of Fe2CuGa in the cubic phase is the Hg2CuTi type structure with the ferromagnetic state. The phase transformation from cubic to tetragonal structure is nearly volume conserving, which is a characteristic of shape memory alloy. The total moments are 4.48 and 4.56 /_LB/f. u. for the austenite and martensite, respectively. The elastic constants of Fe2CuGa are predicted. The cubic structure is mechanically instable while the tetragonal structure is mechanically stable. By analyzing the ratio between the bulk and shear modulus, it is found that Fe2CuGa is ductile in nature. The origin of the martensitic transition is discussed based on the density of states.