Local structure distortion and spin Hamiltonian parameters of oxide-diluted magnetic semiconductor Mn-doped ZnO

【摘要】 The local structure distortion,the spin Hamiltonian(SH) parameters,and the electric fine structure of the ground state for Mn2+(3d5) ion in ZnO crystals are systematically investigated,where spin-spin(SS),spin-other-orbit(SOO) and orbit-orbit(OO) magnetic interactions,besides the well-known spin-orbit(SO) coupling,are taken into account for the first time,by using the complete diagonalization method.The theoretical results of the second-order zero-field splitting(ZFS) parameter D,the fourth-order ZFS parameter(a-F),the Zeeman g-factors:g// and g⊥,and the energy differences of the ground state:δ1 and δ2 for Mn2+ in Mn2+:ZnO are in good agreement with experimental measurements when the three O2-ions below the Mn2+ ion rotate by 1.085° away from the [111]-axis.Hence,the local structure distortion effect plays an important role in explaining the spectroscopic properties of Mn2+ ions in Mn2+:ZnO crystals.It is found for Mn2+ ions in Mn2+:ZnO crystals that although the SO mechanism is the most important one,the contributions to the SH parameters,made by other four mechanisms,i.e.SS,SOO,OO,and SO-SS-SOO-OO mechanisms,are significant and should not be omitted,especially for calculating ZFS parameter D.更多还原

【Abstract】 The local structure distortion,the spin Hamiltonian(SH) parameters,and the electric fine structure of the ground state for Mn2+(3d5) ion in ZnO crystals are systematically investigated,where spin-spin(SS),spin-other-orbit(SOO) and orbit-orbit(OO) magnetic interactions,besides the well-known spin-orbit(SO) coupling,are taken into account for the first time,by using the complete diagonalization method.The theoretical results of the second-order zero-field splitting(ZFS) parameter D,the fourth-order ZFS parameter(a-F),the Zeeman g-factors:g// and g⊥,and the energy differences of the ground state:δ1 and δ2 for Mn2+ in Mn2+:ZnO are in good agreement with experimental measurements when the three O2-ions below the Mn2+ ion rotate by 1.085° away from the [111]-axis.Hence,the local structure distortion effect plays an important role in explaining the spectroscopic properties of Mn2+ ions in Mn2+:ZnO crystals.It is found for Mn2+ ions in Mn2+:ZnO crystals that although the SO mechanism is the most important one,the contributions to the SH parameters,made by other four mechanisms,i.e.SS,SOO,OO,and SO-SS-SOO-OO mechanisms,are significant and should not be omitted,especially for calculating ZFS parameter D.更多还原