Haripriya G R, Nair Harikrishnan S, Pradheesh R, Rayaprol S, Siruguri V, Singh Durgesh, Venkatesh R, Ganesan V, Sethupathi K, Sankaranarayanan V
Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai-600036, India.
J Phys Condens Matter. 2017 Nov 29;29(47):475804. doi: 10.1088/1361-648X/aa919e. Epub 2017 Nov 6.
We report the experimental observation of spin reorientation in the double perovskite HoFeCoO. The magnetic phase transitions in this compound are characterized and studied through magnetization and specific heat, and the magnetic structures are elucidated through neutron powder diffraction. Two magnetic phase transitions are observed in this compound-one at [Formula: see text] K, from paramagnetic to antiferromagnetic, and the other at [Formula: see text] K, from a phase with mixed magnetic structures to a single phase through a spin reorientation process. The magnetic structure in the temperature range 200-45 K is a mixed phase of the irreducible representations [Formula: see text] and [Formula: see text], both of which are antiferromagnetic. The phase with mixed magnetic structures that exists in HoFeCoO gives rise to a large thermal hysteresis in magnetization that extends from 200 K down to the spin reorientation temperature. At T , the magnetic structure transforms to [Formula: see text]. Though long-range magnetic order is established in the transition metal lattice, it is seen that only short-range magnetic order prevails in the Ho lattice. Our results should motivate further detailed studies on single crystals in order to explore the spin reorientation process, spin switching and the possibility of anisotropic magnetic interactions giving rise to electric polarization in HoFeCoO.
我们报道了双钙钛矿HoFeCoO中自旋重取向的实验观察结果。通过磁化强度和比热对该化合物中的磁相变进行了表征和研究，并通过中子粉末衍射阐明了磁结构。在该化合物中观察到两个磁相变：一个在[公式：见原文]K，从顺磁相转变为反铁磁相；另一个在[公式：见原文]K，通过自旋重取向过程从具有混合磁结构的相转变为单相。200 - 45 K温度范围内的磁结构是不可约表示[公式：见原文]和[公式：见原文]的混合相，二者均为反铁磁相。HoFeCoO中存在的具有混合磁结构的相在磁化强度中产生了从200 K一直延伸到自旋重取向温度的大的热滞现象。在T时，磁结构转变为[公式：见原文]。尽管在过渡金属晶格中建立了长程磁有序，但可以看到在Ho晶格中仅存在短程磁有序。我们的结果应促使对单晶进行进一步详细研究，以探索HoFeCoO中的自旋重取向过程、自旋开关以及各向异性磁相互作用产生极化的可能性。
