TY  - JOUR
AU  - Li, Kunkun
AU  - Jin, Shifeng
AU  - Guo, Jiangang
AU  - Xu, Yanping
AU  - Su, Yixi
AU  - Feng, Erxi
AU  - Liu, Yu
AU  - Zhou, Shengqiang
AU  - Ying, Tianping
AU  - Li, Shiyan
AU  - Wang, Ziqiang
AU  - Chen, Gang
AU  - Chen, Xiaolong
TI  - Double-peak specific heat and spin freezing in the spin-2 triangular lattice antiferromagnet FeAl2Se4
JO  - Physical review / B
VL  - 99
IS  - 5
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2019-01585
SP  - 054421
PY  - 2019
AB  - We report the properties of a triangular lattice iron-chalcogenide antiferromagnet FeAl2Se4.The spin susceptibility reveals a significant antiferromagnetic interaction with a Curie-Weiss temperature ΘCW≃−200K and a spin-2 local moment. Despite a large spin and a large ∣∣ΘCW∣∣, the low-temperature behaviors are incompatible with conventional classical magnets. No long-range order is detected down to 0.4 K. Similar to the well-known spin-1 magnet NiGa2S4, the specific heat of FeAl2Se4 exhibits a double-peak structure and a T2 power law at low temperatures, which are attributed to the underlying quadrupolar spin correlations and the Halperin-Saslow modes, respectively. The spin freezing occurs at ∼14K, below which the relaxation dynamics is probed by the ac susceptibility. Our results are consistent with the early theory for the spin-1 system with Heisenberg and biquadratic spin interactions. We argue that the early proposal of the quadrupolar correlation and gauge glass dynamics may be well extended to FeAl2Se4. Our results provide useful insights about the magnetic properties of frustrated quantum magnets with high spins.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000459221500010
DO  - DOI:10.1103/PhysRevB.99.054421
UR  - https://juser.fz-juelich.de/record/860942
ER  -