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.