INVESTIGADORES
GRIGERA Santiago Andres
artículos
Título:
Unconventional Magnetization Processes and Thermal Runaway in Spin-Ice Dy2Ti2O7
Autor/es:
D. SLOBINSKY; C. CASTELNOVO; R. A. BORZI; A. GIBBS; R. MOESSNER; A, P. MACKENZIE; S. A. GRIGERA
Revista:
PHYSICAL REVIEW LETTERS
Editorial:
AMER PHYSICAL SOC
Referencias:
Año: 2010 vol. 105 p. 26720501 - 26720504
ISSN:
0031-9007
Resumen:
We investigate the nonequilibrium behavior of the spin-ice Dy2Ti2O7 by studying its magnetization as a
function of the field sweep rate. Below the enigmatic freezing temperature Tequil 600 mK, we find
that even the slowest sweeps fail to yield the equilibrium magnetization curve and instead give an initially
much flatter curve. For higher sweep rates, the magnetization develops sharp steps accompanied by
similarly sharp peaks in the temperature of the sample. We ascribe the former behavior to the energy
barriers encountered in the magnetization process, which proceeds via flipping of spins on filaments traced
out by the field-driven motion of the gapped, long-range interacting magnetic monopole excitations. The
peaks in temperature result from the released Zeeman energy not being carried away efficiently; the
resulting heating triggers a chain reaction.