We present magnetization (M) data of the d-metal alloy Ni1-xVx at vanadium concentrations close to xx ~ 11.4% where the onset of long-range ferromagnetic (FM) order is suppressed to zero temperature. Above xc, the temperature (T) and magnetic field (H) dependencies of the magnetization are best described by simple nonuniversal power laws. the exponents of M/H ~ T γ and M ~ Hα are related by 1-γ=α for wide temperature (10c to γ<0.1 for x=15%. This behavior is not compatible with either classical or quantum critical behavior in a clean 3D FM. Instead it closely follows the predictions for a quantum Griffiths phase associated with a quantum phase transition in a disordered metal. Deviations at the lowest temperatures hint at a freezing of large clusters and the onset of a cluster glass phase.
S. Ubaid-Kassis et al., "Quantum Griffiths Phase in the Weak Itinerant Ferromagnetic Alloy Ni1-xVx," Physical Review Letters, American Physical Society (APS), Feb 2010.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevLett.104.066402
National Science Foundation (U.S.)
Keywords and Phrases
Nanocrystalline Alloys; Phase Transitions; Ferromagnetic materials; Ferromagnetism; Magnetic fields
Article - Journal
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