单斜晶系TbFe$_{2}$D$_{4.2}$氘化物的亚铁磁结构测定及其随温度与强磁场的演化规律
Determination of the ferrimagnetic structure of monoclinic TbFe$_{2}$D$_{4.2}$ deuteride and its evolution versus temperature and high magnetic field
AI总结：
本研究结合磁性测量与中子衍射实验，测定了单斜TbFe$_{2}$D$_{4.2}$的亚铁磁基态结构，揭示了其磁矩、结构随温度和强磁场的演化规律及转变机制。
AI中文摘要：
本研究结合多种磁性测量手段（包括强脉冲磁场测量）与随温度、外加磁场变化的中子衍射实验，探究了单斜晶系TbFe$_{2}$D$_{4.2}$的磁学性质。TbFe$_{2}$D$_{4.2}$呈现亚铁磁基态，其中Tb磁矩M$_{Tb}$=8.2(2) $μ$$_{B}$，Fe磁矩M$_{Fe}$=2.1(2) $μ$$_{B}$。在4.2 K下观测到与Tb磁矩相关的强磁各向异性，磁场达50 T时仍未达到饱和；此外，在3 T和29 T磁场下观测到两次变磁转变。升温过程中，Tb磁矩逐渐减小，而Fe磁矩在150 K以下保持恒定。在160 K时，Tb和Fe磁矩均急剧下降，同时因Fe亚晶格的巡游电子变磁行为，晶胞体积发生0.38%的收缩。该转变温度比YFe$_{2}$D$_{4.2}$高76 K，原因在于晶胞体积增大以及Fe与Tb磁矩间的交换相互作用增强。该氘化物在220 K以上转变为顺磁态。
英文摘要：
The magnetic properties of monoclinic TbFe$_{2}$D$_{4.2}$ have been investigated by combining different magnetic measurements, including those involving a high pulsed magnetic field, with neutron diffraction experiments versus temperature and applied field. TbFe$_{2}$D$_{4.2}$ displays a ferrimagnetic ground state with M$_{Tb}$ = 8.2(2) $μ$$_{B}$ and M$_{Fe}$ = 2.1(2) $μ$$_{B}$. At 4.2 K a large magnetic anisotropy related to the Tb moments is observed, as saturation is not reached at 50 T. In addition, two metamagnetic transitions are observed for fields of 3 and 29 T. Upon heating, the Tb moment decreases progressively whereas the Fe moment remains constant up to 150 K. At 160 K both Tb and Fe moments sharply decrease, and a 0.38% contraction of the cell volume is observed due to an itinerant electron metamagnetic behavior of the Fe sublattice. This transition temperature is 76 K higher than that of YFe$_{2}$D$_{4.2}$ due to an increase in cell volume, as well as exchange interactions between the Fe and Tb moments. The deuteride becomes paramagnetic above 220 K.
