Abstract
An Ising model including field randomness and bond randomness is studied by renormalization-group theory in spatial dimensions and 3. In with field randomness but no randomness, ferromagnetic and paramagnetic phases occur with no intervening spin-glass phase. Also in at sufficient randomness, a spin-glass phase occurs, but is replaced by the paramagnetic phase for any nonzero random field, also implying its disappearance for any nonzero uniform field. In no ferromagnetic phase under random fields and no spin-glass phase occur. Global phase diagrams uniting the random-field and spin-glass problems are evaluated. The strong violation of critical phenomena universality, previously found adjoining random-bond tricriticality in is seen here in
- Received 31 July 1997
DOI:https://doi.org/10.1103/PhysRevB.57.426
©1998 American Physical Society