Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
J Phys Condens Matter. 2013 Apr 10;25(14):146001. doi: 10.1088/0953-8984/25/14/146001. Epub 2013 Mar 11.
Neutron powder diffraction experiments have been performed to investigate the nature of magnetic ordering, as a function of temperature (1.5-100 K) and magnetic field (0, 2 and 4 T), in the compound Ca3Co1.8Fe0.2O6. In zero applied field, the compound orders magnetically in the incommensurate spin density wave (SDW) structure (TN ∼ 20 K). Under an applied field of ∼2 T, an incommensurate-to-commensurate magnetic phase transition has been observed. With a further increase in the magnetic field (∼4 T), the commensurate magnetic structure transforms into a ferrimagnetic structure. In zero applied field, magnetic short-range ordering (SRO) coexists with the SDW long-range ordering (LRO) at all temperatures below TN. In an applied magnetic field (2 and 4 T), SRO is converted into LRO only over the temperature range 12-20 K; however, below ∼12 K, an increase in the volume fraction of the SRO has been observed. The correlation length for the SRO (below ∼12 K) also gets affected by the application of a field.
已进行中子粉末衍射实验，以研究在化合物 Ca3Co1.8Fe0.2O6 中，温度（1.5-100 K）和磁场（0、2 和 4 T）对磁有序的影响。在零外磁场下，该化合物以非简谐自旋密度波（SDW）结构（TN∼20 K）有序化。在约 2 T 的外加磁场下，观察到非谐到谐磁相变。随着磁场的进一步增加（约 4 T），谐磁结构转变为亚铁磁结构。在零外磁场下，低于 TN 的所有温度下，磁短程有序（SRO）与 SDW 长程有序（LRO）共存。在外加磁场（2 和 4 T）下，仅在 12-20 K 的温度范围内，SRO 转化为 LRO；然而，在约 12 K 以下，观察到 SRO 的体积分数增加。SRO 的相关长度（低于约 12 K）也受到外加磁场的影响。
