English

Collapse of Kondo state and ferromagnetic quantum phase transition in YbFe$_2$Zn$_{20}$

Strongly Correlated Electrons 2019-07-23 v1

Abstract

We present the electrical resistivity data under application of pressures up to \sim 26 GPa and down to 50 mK temperatures on YbFe2_2Zn20_{20}. We find a pressure induced magnetic phase transition with an onset at pcp_c=18.2±\pm0.8 GPa. At ambient pressure, YbFe2_2Zn20_{20} manifests a heavy fermion, nonmagnetic ground state and the Fermi liquid behavior at low temperatures. As pressure is increased, the power law exponent in resistivity, nn, deviates significantly from Fermi liquid behavior and tends to saturate with nn = 1 near pcp_c. A pronounced resistivity maximum, TmaxT_\text{max}, which scales with Kondo temperature is observed. TmaxT_\text{max} decreases with increasing pressure and flattened out near pcp_c indicating the suppression of Kondo exchange interaction. For p>pcp>p_c, TmaxT_\text{max} shows a sudden upward shift, most likely becoming associated with crystal electric field scattering. Application of magnetic field for p>pcp>p_c broadens the transition and shifts it toward the higher temperature, which is a typical behavior of the ferromagnetic transition. The magnetic transition appears to abruptly develop above pcp_c, suggesting probable first-order (with changing pressure) nature of the transition; once stabilized, the ordering temperature does not depend on pressure up to \sim 26 GPa. Taken as a whole, these data suggest that YbFe2_2Zn20_{20} has a quantum phase transition at pcp_c = 18.2 GPa associated with the avoided quantum criticality in metallic ferromagnets.

Keywords

Cite

@article{arxiv.1808.01367,
  title  = {Collapse of Kondo state and ferromagnetic quantum phase transition in YbFe$_2$Zn$_{20}$},
  author = {Udhara S. Kaluarachchi and Li Xiang and Jianjun Ying and Tai Kong and Viktor Struzhkin and Alexander Gavriliuk and Sergey L. Bud'ko and Paul C. Canfield},
  journal= {arXiv preprint arXiv:1808.01367},
  year   = {2019}
}