The critical state and the Hc1 field in YBa2Cu3O7-x, single crystals
Kartsovnik M. V., Larkin V. A., Ryazanov V. V., Sidorov N. S., Shchegolev I. F.
The static magnetization of strongly twinned YBa2Cu307 _ x single crystals has been measured in weak fields. The critical current density of magnetization with an exponential temperature dependence has been determined. The anisotropy of the lower critical field #cl is approximately equal to 6. The field Hcl increases linearly as the temperature is lowered to 40 K.