Quantum Griffiths phase in the weak itinerant ferromagnetic alloy Ni(1-x)V(x).
Phys Rev Lett
; 104(6): 066402, 2010 Feb 12.
Article
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| MEDLINE
| ID: mdl-20366837
ABSTRACT
We present magnetization (M) data of the d-metal alloy Ni(1-x)V(x) at vanadium concentrations close to x(c) approximately = 11.4% where the onset of long-range ferromagnetic (FM) order is suppressed to zero temperature. Above x(c), the temperature (T) and magnetic field (H) dependencies of the magnetization are best described by simple nonuniversal power laws. The exponents of M/H approximately T(-gamma) and M approximately H(alpha) are related by 1-gamma = alpha for wide temperature (10 < T < or = 300 K) and field (H < or = 5 T) ranges. gamma is strongly x dependent, decreasing from 1 at x approximately = x(c) to gamma < 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.
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Banco de datos:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos