HIGH-RESOLUTION SPECIFIC-HEAT EXPERIMENTS ON THE MELTING LINE OF THE VORTEX-GLASS IN YBA2CU3OX - OBSERVATION OF 2ND-ORDER TRANSITIONS UP TO14 TESLAS

Steps in the specific heat below T-c attibuted to the melting of a vor tex glass are investigated as a function of the field (B less than or equal to 14T) and oxygen concentration (6.9 less than or equal to x le ss than or equal to 7) for an YBa2Cu3Ox crystal grown by the Travellin g Solvent Floating Zone Melting (TSFZM) technique. Critical points and scaling properties are discussed.