Canfield, P. C.Choi, S.-M.Gammel, P. L.López, D.Lynn, J. W.2004-12-032004-12-0320012001http://hdl.handle.net/2003/97610.17877/DE290R-8541enThe American Physical SocietyPhysical Review Letters530Direct Observation of Spontaneous Weak Ferromagnetism in the Superconductor ErNi2B2C10.1103/PhysRevLett.87.107001article (journal)