This title appears in the Scientific Report : 2019 

Coexistence of Ferromagnetic and Stripe-Type Antiferromagnetic Spin Fluctuations in YFe 2 Ge 2
Wo, Hongliang
Wang, Qisi / Shen, Yao / Zhang, Xiaowen / Hao, Yiqing / Feng, Yu / Shen, Shoudong / He, Zheng / Pan, Bingying / Wang, Wenbin / Nakajima, K. / Ohira-Kawamura, S. / Steffens, P. / Boehm, M. / Schmalzl, K. / Forrest, T. R. / Matsuda, M. / Zhao, Yang / Lynn, J. W. / Yin, Zhiping / Zhao, Jun (Corresponding author)
Streumethoden; JCNS-2
Streumethoden; PGI-4
Physical review letters, 122 (2019) 21, S. 217003
College Park, Md. APS 2019
Journal Article
Jülich Centre for Neutron Research (JCNS)
Materials and Processes for Energy and Transport Technologies
Quantum Condensed Matter: Magnetism, Superconductivity
Controlling Collective States
Controlling Collective States
Please use the identifier: in citations.
Please use the identifier: in citations.
We report neutron scattering measurements of single-crystalline YFe2Ge2 in the normal state, which has the same crystal structure as the 122 family of iron pnictide superconductors. YFe2Ge2 does not exhibit long-range magnetic order but exhibits strong spin fluctuations. Like the iron pnictides, YFe2Ge2 displays anisotropic stripe-type antiferromagnetic spin fluctuations at (π, 0, π). More interesting, however, is the observation of strong spin fluctuations at the in-plane ferromagnetic wave vector (0, 0, π). These ferromagnetic spin fluctuations are isotropic in the (H, K) plane, whose intensity exceeds that of stripe spin fluctuations. Both the ferromagnetic and stripe spin fluctuations remain gapless down to the lowest measured energies. Our results naturally explain the absence of magnetic order in YFe2Ge2 and also imply that the ferromagnetic correlations may be a key ingredient for iron-based materials.