Quantum Critical Point in the Itinerant Ferromagnet Ni1−xRhx

We report a chemical substitution-induced ferromagnetic quantum critical point in polycrystalline Ni1−xRhx alloys. Through magnetization and muon spin relaxation measurements, we show that the ferromagnetic ordering temperature is suppressed continuously to zero at xcrit=0.375 while the magnetic volume fraction remains 100% up to xcrit, pointing to a second order transition. Non-Fermi liquid behavior is observed close to xcrit, where the electronic specific heat Cel/T diverges logarithmically, while immediately above xcrit the volume thermal expansion coefficient αV/T and the Grüneisen ratio Γ=αV/Cel both diverge logarithmically in the low temperature limit, further indication of a ferromagnetic quantum critical point in Ni1−xRhx.