Persistence of a non-antiphase modulated magnetic structure to T → 0 in the heavy electron compound YbPtAl
Persistence of a non-antiphase modulated magnetic structure to T → 0 in the heavy electron compound YbPtAl
复制标题
重电子化合物 YbPtAl 中非反相调制磁结构持续到 T → 0
DOI：
10.1209/epl/i2000-00512-5
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
O. Trovarelli
中科院分区：
文献类型：
--
作者：
P. Bonville;B. Malaman;E. Ressouche;J. Sanchez;M. Abd;C. Geibel;O. Trovarelli
用~（170）Yb穆斯堡尔谱和中子衍射方法对重电子化合物YbPtAl（TN 5.8K）进行了低至0.025K的测量。在0.025 K，穆斯堡尔谱证据的磁矩的非平方调制，与晶格间距不相称。这是Kramers局域矩Yb基系统的第一个明确的例子，其中Kondo单线态基态允许调制的磁性结构持续到T → 0 K。可以测量调制的三阶和五阶谐波，并且可以跟踪它们在0.025 K到5 K之间的热变化。在3 K的两个谐波的突然减少是伴随着在比热的峰值，这表明一个一阶相变的调制转换成一个纯正弦波。
Measurements by 170Yb Mossbauer spectroscopy down to 0.025 K and by neutron diffraction down to 1.7 K have been performed in the heavy electron compound YbPtAl (TN 5.8 K). At 0.025 K, the Mossbauer spectrum evidences a non-square modulation of the magnetic moment, incommensurate with the lattice spacings. This is the first clear example of a Kramers local moment Yb-based system where the Kondo singlet ground state allows a modulated magnetic structure to persist to T → 0 K. The 3rd- and 5th-order harmonics of the modulation could be measured, and their thermal variation was followed from 0.025 K to 5 K. An abrupt decrease of both harmonics at 3 K is concomitant with a peak in the specific heat, suggesting a first-order phase transition where the modulation transforms into a pure sine wave.