Melting of "Porous" Vortex Matter

S. S. BANERJEE; A. SOIBEL; Y. MYASOEDOV; M. RAPPAPORT; E. ZELDOV; M. MENGHINI; YANINA FASANO; F. DE LA CRUZ; C. J. VAN DER BEEK; M. KONCZYKOWSKI; T. TAMEGAI

PHYSICAL REVIEW LETTERS

Año: 2003 vol. 90 p. 87004 - 87007

0031-9007

Bitter decoration and magneto-optical studies reveal that in heavy-ion irradiated superconductors, a “porous” vortex matter is formed when vortices outnumber columnar defects. In this state ordered vortex crystallites are embedded in the “pores” of a rigid matrix of vortices pinned on columnar defects. The crystallites melt through a first-order transition while the matrix remains solid. The melting temperature increases with density of columnar defects and eventually turns into a continuous transition. At high temperatures a sharp kink in the melting line is found, signaling an abrupt change from crystallite melting to melting of the rigid matrix.