Random-field and glassy dynamics in a diluted Ising antiferromagnet:
Departamento de Física, Universidad Nacional de Colombia
A.A. 127, Manizales, Colombia
2 Departamento de Física, Universidade Federal de Pernambuco 50670-901, Recife, PE, Brasil
Accepted: 10 February 2000
The random-field Ising model (RFIM) system is studied by magnetization and dynamic susceptibility measurements, under finite dc applied fields (H). For , the magnetic behaviour is compatible with a long-range ordered (LRO) antiferromagnetic (AF) ground state, which undergoes a phase transition (PT) at a critical temperature . For higher H, the LRO configuration becomes unstable and the PT is destroyed. A glassy dynamics emerges in the upper part of the (H,T) phase diagram. Our results reconcile earlier concepts associated with the weak RFIM problem with recent experimental data in .
PACS: 75.50.Lk – Spin glasses and other random magnets / 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.) / 75.30.Kz – Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.)
© EDP Sciences, 2000