Pinning induced magnetostriction in ceramic high temperature superconductors

Transverse and longitudinal magnetostriction was measured in ceramic YBa2Cu 3O7-delta and Hg0.8Pb0.2Ba2Ca2Cu3O8+delta superconductors by the strain gau ge technique. The measurements were performed in an external magnetic field up to 12 T. The observed magnetostriction was shown to consist of two comp onents. The first one is connected with the intragrain and the second one w ith the intergrain screening currents. Both components of the magnetostrict ion were analyzed independently in frames of an isotropic theory of the pin ning induced magnetostriction. (C) 1999 Elsevier Science B.V. All rights re served.