Contents

16 November 2001
Vol 294, Issue 5546

About The Cover

Cover image expansion

COVER Calculated neutron scattering pattern for the "spin ice" state where spins (magnetic moments) mimic the proton disorder in water ice. The study of spin ice materials such as Ho2Ti2O7 may shed light on the role of competing or frustrated interactions in many areas of condensed matter science. 1483 [Image: Byron den Hertog]