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采用基于赝势平面波基组的第一性原理方法对一系列具有钙钛矿结构的复合稀土铁氧化物RFeO3(R=镧系稀土元素)的构型和电子结构进行了系统研究.考察了铁磁(FM)和反铁磁(AFM)两种磁结构,其中AFM型在常温下更为稳定,且其构型优化结果更接近于实验测量值.不论是FM还是AFM构型,R原子的磁距均与自由R3+离子相同;对于Fe原子,在FM结构中的磁距较AFM类型来得小;随着R原子序数的增加,两种磁结构中Fe原子的磁距均呈减小趋势;对于相同类型的RFeO3化合物,具有非常类似的能带结构,其中AFM构型在费米能级处存在明显的带隙,而FM型化合物则具有金属特性.
The first-principle method based on the pseudopotential plane wave-based group was used to systematically study the configurations and electronic structures of a series of rare earth oxides RFeO3 (R = lanthanide rare earth elements) with perovskite structure. Magnetic (FM) and antiferromagnetic (AFM) magnetic structures, of which AFM type at room temperature is more stable, and its configuration optimization results closer to the experimental measurements.Whether FM or AFM configuration, R atom The magnetic moments are the same as the free R3 + ions. For Fe atoms, the magnetic distances in the FM structure are smaller than those in the AFM. As the atomic number of R increases, the magnetic moments of Fe atoms in both magnetic structures decrease. For the same type of RFeO3 compounds, there is a very similar band structure in which the AFM configuration has a significant bandgap at the Fermi level, whereas the FM-type compounds have metallic properties.