DISLOCATIONS USED TO PROBE THE DEFECT STATE OF AN IONIC-CRYSTAL LATTICE EXCITED BY A PULSED MAGNETIC-FIELD

paper presents the results of an investigation into the effect of a pu lsed magnetic field on the state of linear and point defects in ionic crystals. For different amplitudes (1-7 T) and pulse lengths (3 x 10(- 5) to 10(2) s) of the pulsed field the kinetics of the transformation of defects inter a new state and their relaxation after the field is t urned off are studied in the temperature range 77-400 K. It is found t hat the relaxation of the states of point defects is mainly through re combination, and the change of state of the dislocations and of the po int defects contribute nonadditively to the change in the dislocation mobility, The exposure of the crystal to a magnetic held leads to an i ncrease in the dislocation mobility when the sample is mechanically st ressed and to a decrease in the dislocation displacement with a second field pulse. (C) 1997 American Institute of Physics.