Phase segregation in Pb:GeSbTe chalcogenide system J. Kumar, M. Ahmad, R. Chander, R. Thangaraj and T. S. Sathiaraj Eur. Phys. J. Appl. Phys., 41 1 (2008) 13-18 Published online: 19 December 2007 DOI: 10.1051/epjap:2007173