Huang C-L, Hallas A M, Grube K, Kuntz S, Spieß B, Bayliff K, Besara T, Siegrist T, Cai Y, Beare J, Luke G M, Morosan E
Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
Department of Physics and Astronomy and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Phys Rev Lett. 2020 Mar 20;124(11):117203. doi: 10.1103/PhysRevLett.124.117203.
We report a chemical substitution-induced ferromagnetic quantum critical point in polycrystalline Ni_{1-x}Rh_{x} alloys. Through magnetization and muon spin relaxation measurements, we show that the ferromagnetic ordering temperature is suppressed continuously to zero at x_{crit}=0.375 while the magnetic volume fraction remains 100% up to x_{crit}, pointing to a second order transition. Non-Fermi liquid behavior is observed close to x_{crit}, where the electronic specific heat C_{el}/T diverges logarithmically, while immediately above x_{crit} the volume thermal expansion coefficient α_{V}/T and the Grüneisen ratio Γ=α_{V}/C_{el} both diverge logarithmically in the low temperature limit, further indication of a ferromagnetic quantum critical point in Ni_{1-x}Rh_{x}.
我们报道了在多晶Ni₁₋ₓRhₓ合金中由化学取代诱导的铁磁量子临界点。通过磁化和μ子自旋弛豫测量，我们表明，在x₍crit₎ = 0.375时，铁磁有序温度连续降至零，而磁体积分数在达到x₍crit₎之前保持100%，这表明是二级相变。在接近x₍crit₎处观察到非费米液体行为，其中电子比热Cₑₗ/T呈对数发散，而在x₍crit₎之上，体积热膨胀系数αᵥ/T和格林艾森比Γ = αᵥ/Cₑₗ在低温极限下均呈对数发散，进一步表明Ni₁₋ₓRhₓ中存在铁磁量子临界点。
