A model of localized highly frustrated ferromagnetism is presented: kagomé spin ice. Using analytical and Monte Carlo calculations its massive ground-state entropy is evaluated. Monte Carlo calculations are also used to explore the phases in the presence of further-neighbor interactions and applied fields. The importance of thermal spin fluctuations and their ability to stabilize a variety of magnetic structures is clearly manifested. Remarkably, some of these phases are only partially ordered and present both disordered and ordered sublattices.

• Received 26 July 2001

DOI:https://doi.org/10.1103/PhysRevB.66.144407