Geometrical frustration and incommensurate magnetic ordering in CePdAl: a low-temperature neutron-diffraction study
Geometrical frustration and incommensurate magnetic ordering in CePdAl: a low-temperature neutron-diffraction study
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CePdAl 中的几何挫败和不相称的磁序：低温中子衍射研究
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
B. Brandt
中科院分区：
文献类型：
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作者：
Lukas Keller;A. Donni;Hideaki Kitazawa;B. Brandt
通过对高质量多晶样品的中子粉末衍射测量，研究了重费米子化合物CePdAl中Ce3+磁矩的有序性。磁性离子的三角配位对称性导致几何受挫，并导致无公度的反铁磁结构，表现出有序和受挫的无序Ce矩共存。磁传播矢量在Tn以下表现出明显的温度依赖性，并锁定在k=FRAC\BOX1\BOX2\BOX2$，0，τ，τ=0.351，低于1.9K。180mK时的磁结构可以明确地确定，即使在最低温度下也可以观察到有序和无序磁矩的共存。可以排除第二磁相变。
Abstract.The ordering of the Ce3+ magnetic moments in the heavy-fermion compound CePdAl was investigated by means of neutron powder diffraction measurements of high-quality polycrystalline samples at temperatures down to 180 mK. The triangular coordination symmetry of the magnetic ions gives rise to geometrical frustration and leads to an incommensurate antiferromagnetic structure, exhibiting a coexistence of ordered and frustrated disordered Ce moments. The magnetic propagation vector shows a pronounced temperature dependence below TN and locks in to k= $\frac\Box1\Box\Box2\Box$,0,τ , τ=0.351, below 1.9 K. The magnetic structure at 180 mK could unambiguously be determined and the coexistence of ordered and disordered Ce moments is observed even at the lowest temperatures. A second magnetic phase transition can be excluded.