Hall effect anomaly and low-temperature metamagnetism in the Kondo compound CeAgBi2
Hall effect anomaly and low-temperature metamagnetism in the Kondo compound CeAgBi2
复制标题
DOI：
10.1103/physrevb.93.075149
复制
发表时间：
2015-08
影响因子：
3.7
通讯作者：
S. Thomas;P. Rosa;SungBin Lee;S. Parameswaran;Z. Fisk;J. Xia
中科院分区：
文献类型：
--
作者：
S. Thomas;P. Rosa;SungBin Lee;S. Parameswaran;Z. Fisk;J. Xia
重费米子(HF)材料由于其局域力矩和巡回电子之间的强Kondo耦合而显示出丰富的现象。他们研究中的一个中心问题是了解磁序和电荷传输之间的相互作用，以及它在稳定物质的新量子相方面的作用。在这方面特别有希望的是一族四方金属间化合物$\mathm{Ce}T{X}_{2}$(其中$T$表示过渡金属，$X$表示pNictogen)，其中包括各种表现出$T$-线性电子比热${\mathbf{C}}_{e}\ensuremath{\sim}\ensuremath{\gamma}T$，的HF化合物$\ensuremath{\gamma}\ensuremath{\sim}20--500\phantom{\rule{0.16em}{0ex}}\mathrm{mJ}\phantom{\rule{0.16em}{0ex}}{\mathrm{mol}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}2}$，反映了从小到适度的有效质量增强。在这里，我们利用磁测量和输运测量研究了高质量的{\mathm{CeAgBi}}{2}$的低温场调谐相图。我们发现${T}_{N}=6.4\phantom{\rule{0.16em}{0ex}}\mathrm{K}$的反铁磁相变具有弱磁各向异性，易轴沿着$c轴，类似于先前报道的$({T}_{N}=6.1\phantom{\rule{0.16em}{0ex}}\mathrm{K})$.这种情况，加上两个各向异性的Ruderman-Kittel-Kasuya-Yosida相互作用的存在，导致了一个丰富的场调谐磁相图，包括五个一阶和二阶的超磁相变。此外，我们还揭示了场Hl54\phantom{\Rule{4.pt}{0ex}}\mathm{Koe}$的反常霍尔贡献，当通过57、78和84Koe的三次跃迁调谐$H$时，这一贡献发生了剧烈的变化，这表明费米面是在变磁跃迁的一个子集中重建的。
Heavy fermion (HF) materials exhibit a rich array of phenomena due to the strong Kondo coupling between their localized moments and itinerant electrons. A central question in their study is to understand the interplay between magnetic order and charge transport, and its role in stabilizing new quantum phases of matter. Particularly promising in this regard is a family of tetragonal intermetallic compounds $\mathrm{Ce}T{X}_{2}$ (where $T$ denotes transition metal and $X$ denotes pnictogen), which includes a variety of HF compounds showing $T$-linear electronic specific heat ${\mathbf{C}}_{e}\ensuremath{\sim}\ensuremath{\gamma}T$, with $\ensuremath{\gamma}\ensuremath{\sim}20--500\phantom{\rule{0.16em}{0ex}}\mathrm{mJ}\phantom{\rule{0.16em}{0ex}}{\mathrm{mol}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}2}$, reflecting an effective-mass enhancement ranging from small to modest. Here, we study the low-temperature field-tuned phase diagram of high-quality ${\mathrm{CeAgBi}}_{2}$ using magnetometry and transport measurements. We find an antiferromagnetic transition at ${T}_{N}=6.4\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ with weak magnetic anisotropy and the easy axis along the $c$ axis, similar to previous reports $({T}_{N}=6.1\phantom{\rule{0.16em}{0ex}}\mathrm{K})$. This scenario, along with the presence of two anisotropic Ruderman-Kittel-Kasuya-Yosida interactions, leads to a rich field-tuned magnetic phase diagram, consisting of five metamagnetic transitions of both first and second order. In addition, we unveil an anomalous Hall contribution for fields $Hl54\phantom{\rule{4.pt}{0ex}}\mathrm{kOe}$, which is drastically altered when $H$ is tuned through a trio of transitions at 57, 78, and 84 kOe, suggesting that the Fermi surface is reconstructed in a subset of the metamagnetic transitions.