Vortex phase diagrams of Bi2Sr2CaCu2O8+y in tilted fields studied by a Hall probe

We studied the vortex phase diagram of Bi2Sr2CaCu2O8+y in tilted fields wit h respect to the c-axis of the crystal through magnetization measurements b y a micro Hall probe. The linear decrease of c-axis component of the meltin g fields. and second peak fields at low temperatures, against the in-plane component breaks down in the limit of both H parallel toc and H parallel to ab. Through the temperature and anisotropy dependence of the phase diagram , we discuss the possible origin of the deviation from the linear dependenc e. (C) 2001 Elsevier Science B.V. All rights reserved.