A-site ion-size effect on the transport and magnetic properties of Ce doping Pr(0.3)Ce(0.2)Ca(x)Sr(0.5-x)MnO(3) (0 <= x <= 0.25)

作者：Shi L^*; Wang Y; Zhou S M; Chu S N; Guo Y Q; Zhao J Y

来源：Journal of Applied Physics, 2011, 109(12): 123909.

DOI：10.1063/1.3597822

The effects of A-site ion-size < r(A)> on the crystal structures, transport and magnetic properties of the perovskite manganese oxide Pr(0.3)Ce(0.2)Ca(x)Sr(0.5-x)MnO (0 <= x <= 0.25) have been investigated. In those compounds, when 0 <= x <= 0.125, the temperatures (T(max)) of the resistivity maximums below Curie Temperature T(C) are correlated with the Kondo-like scattering of Ce(3+) and the onset of antiferromagnetic ordering of Ce(3+) with respect to the Mn-sublattice moments. The decrease of < r(A)> causes the anomalous increase of lattice parameters b, c and unit cell volume, the decrease of the differences of T(C) and T(max), the weakening of the Kondo-like scattering and magnetic order of Ce(3+), and the enhancement of saturation magnetic moment, which give the evidences of the valence enhancing of Ce ions from +3 toward +4 with < r(A)> decreasing. Although the Ca doping is expected to drive the system toward the antiferromagnetic ground state, the increase of valence of Ce enhances the content of Mn(3+) in the system, which drives the system to the ferromagnetic ground state. The changes of ion-size < r(A)> and the valence of Ce are co-operating on the transport and magnetic properties of the half-doped manganites.

• 出版日期2011-6-15
• 单位中国科学技术大学