Asymmetric ferromagnetic criticality in pyrochlore ferromagnet Lu2V2O7

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（17）
• 页码范围: 1222-1227
• 页数: 6页
• 语种: 英文

摘要

We study the ferromagnetic criticality of the pyrochlore magnet Lu2V2O7 at the ferromagnetic transition Tc ≈ 70K from the isotherms of magnetization M(H) via an iteration process and the Kouvel-Fisher method.The critical exponents associated with the transition are determined:β =0.32(1),γ =1.41(1),and δ =5.38.The validity of these critical exponents is further verified by scaling all the M(H) data in the vicinity of Tc onto two universal curves in the plot of M/|εf versus H/|ε|β+γ,where ε =T/Tc-1.The obtained β and γ values show asymmetric behaviors on the T ＜ Tc and the T ＞ Tc sides,and are consistent with the predicted values of 3D Ising and cubic universality classes,respectively.This makes Lu2V2O7 a rare example in which the critical behaviors associated with a ferromagnetic transition belong to different universality classes.We describe the observed criticality from the Ginzburg-Landau theory with the quartic cubic anisotropy that microscopically originates from the anti-symmetric Dzyaloshinskii-Moriya interaction as revealed by recent magnon thermal Hall effect and theoretical investigations.