中文摘要：

采用基于密度泛函理论框架下的第一性原理方法,结合广义梯度近似研究了Cu掺杂β-Ga2O3系统的磁学特性.计算结果表明,单Cu的掺杂,稳定体系倾向于自旋极化态,且Cu替代八面体的Ga（B）时系统更稳定,容易在实验上形成;Cu掺杂β-Ga2O3呈现出半金属特性,Cu的掺杂引入了2.0μB磁矩,其中局域在Cu原子上的磁矩为0.45μB,其余主要来自于Cu杂质周围的氧原子.由于电荷补偿效应,在Cu掺杂β-Ga2O3系统中引入氧空位时,体系磁矩减小到零.在2个Cu取代Ga的10种构型中,A1-B3构型的能量最低,且显示出铁磁性,磁矩为3.8μB.考虑氧空位后,A1-B3构型的反铁磁性和铁磁性能量差增大,磁矩减小到1.0μB.

英文摘要：

From first-principles calculations based on the density functional theory, the electronic structure and magnetic interactions of Cu-doped β-Ga2O3 were investigated. The calculated results indicate that the ground state is the spin-polarized state and Cu atom tends to substitute the Ga atom at the tetrahedral coordinated site. Cu-doped Ga2O3 shows half-metallic characters with 100 % spin polarization. The magnetic moment of Cu-doped β-Ga2O3 is 2.0μB per cell, which mainly arises from Cu 0. 45βB and the 2p electron of O atoms around Cu dopant. When one oxy- gen vacancy is introduced into Cu-doped β-Ga2O3, the magnetic moment decreases to zero because of the compensation effect. In all the configurations of two Cu atoms substitute either tetrahedral or octahedral sites, A1-B3 configuration has the lowest energy and favors the ferromagnetic ordering, in which the magnetic moment is 3. 8μB. The energy difference between ferromagnetic and anti ferromagnetic states is larger than that of configuration and the magnetic moment decreases to 1.0μB when oxygen vacancy is introduced.