Long-Range Magnetic Interactions Induced by the Lattice Distortions and the Origin of the E-Type Antiferromagnetic Phase in the Undoped Orthorhombic Manganites
Long-Range Magnetic Interactions Induced by the Lattice Distortions and the Origin of the E-Type Antiferromagnetic Phase in the Undoped Orthorhombic Manganites
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DOI：
10.1143/jpsj.78.054710
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发表时间：
2008-12
影响因子：
1.7
通讯作者：
I. Solovyev
中科院分区：
文献类型：
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作者：
I. Solovyev
随着晶格变形量的增加，正交锰氧化物RMnO3(R=La，Pr，Nd，Tb，Ho)经历了从层状A型反铁磁态到锯齿形E型反铁磁态的相变。我们认为这一转变的微观起源。我们的方法由两部分组成。首先，我们建立了一个有效的锰3d带低能模型，并从第一性原理电子结构计算中得到了该模型的参数。然后，我们在Hartree-Fock近似(HFA)下求解该模型，并分析了原子间磁相互作用的行为。我们认为，近邻相互作用随着畸变率的增加而减小，并在一定阶段开始与正交面上较远距离(特别是第二和第三近邻)的原子力显微镜相互作用，从而触发E相的形成。这些相互作用的起源与轨道有序性密切相关，轨道有序性需要…
With the increase of the lattice distortion, the orthorhombic manganites R MnO 3 ( R = La, Pr, Nd, Tb, and Ho) are known to undergo the phase transition from the layered A-type antiferromagnetic (AFM) state to the zigzag E-type AFM state. We consider the microscopic origin of this transition. Our approach consists of the two parts. First, we construct an effective low-energy model for the manganese 3 d -bands and derive parameters of this model from the first-principles electronic structure calculations. Then, we solve this model in the Hartree–Fock approximation (HFA) and analyze the behavior of the interatomic magnetic interactions. We argue that the nearest-neighbor interactions decrease with the increase of the distortion and at certain stage start to compete with the longer range (particularly, second- and third-neighbor) AFM interactions in the orthorhombic ab -plane, which trigger the formation of the E-phase. The origin of these interactions is closely related to the orbital ordering, which takes ...