Avoided ferromagnetic quantum critical point: unusual short-range ordered state in CeFePO.
Avoided ferromagnetic quantum critical point: unusual short-range ordered state in CeFePO.
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DOI：
10.1103/physrevlett.109.216402
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发表时间：
2012-10
影响因子：
8.6
通讯作者：
S. Lausberg;J. Spehling;A. Steppke;A. Jesche;H. Luetkens;A. Amato;C. Baines;C. Krellner;M. Brando;C. Geibel;H. Klauss;F. Steglich
中科院分区：
文献类型：
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作者：
S. Lausberg;J. Spehling;A. Steppke;A. Jesche;H. Luetkens;A. Amato;C. Baines;C. Krellner;M. Brando;C. Geibel;H. Klauss;F. Steglich
通过交流磁化率、比热和μ子自旋弛豫 (μSR) 研究了重费米子系统 CeFePO 单晶中的铈 4f 电子自旋动力学。短程静磁发生在凝固温度 T(g) ≈ 0.7 K 以下，这会阻止系统达到假定的铁磁量子临界点。在μSR中，样本平均μ子不对称函数主要由低于10 K的强烈不均匀自旋涨落主导，并表现出玻璃自旋动力学预期的特征时间场标度关系，有力地证明了合作和临界自旋涨落。整体行为既不能归因于经典自旋玻璃，也不能归因于其他无序驱动机制。
Cerium 4f electronic spin dynamics in single crystals of the heavy-fermion system CeFePO is studied by means of ac susceptibility, specific heat, and muon-spin relaxation (μSR). Short-range static magnetism occurs below the freezing temperature T(g) ≈ 0.7 K, which prevents the system from accessing a putative ferromagnetic quantum critical point. In the μSR, the sample-averaged muon asymmetry function is dominated by strongly inhomogeneous spin fluctuations below 10 K and exhibits a characteristic time-field scaling relation expected from glassy spin dynamics, strongly evidencing cooperative and critical spin fluctuations. The overall behavior can be ascribed neither to canonical spin glasses nor other disorder-driven mechanisms.