Precise magnetization measurements of YBa2Cu3O7- single crystals have found evidence for a bulk phase transition a few degrees below the superconducting critical temperature. The phase transition is indicated by a sudden drop of the lower critical field, Hc1(T), separating a full coherent state at low fields and temperatures, the Meissner state, from a region at higher temperatures where magnetic excitations are induced at H=0.
|Number of pages||4|
|Journal||Physical Review B|
|State||Published - 1 Jan 1991|