MASS AND VELOCITY DISTRIBUTIONS OF LASER-ABLATED SPECIES EJECTED FROMA COLOSSAL MAGNETORESISTANT PR0.67SR0.33MNO3 TARGET

Pulsed laser ablation of the colossal magnetoresistant (CMR) material, Pr0.67Sr0.33MnO3, has been investigated using a time-resolved quadrup ole mass spectrometric method under both 355 nm and 532 nm laser irrad iation. Mass and velocity distributions of the ionic and neutral ablat ed species are measured. The major ablated species include metal atoms and ions as well as binary metal oxides. The time-of-flight (TOF) spe ctra of ablated species are well fitted by a Maxwell-Boltzmann distrib ution with a center-of-mass velocity. The kinetic energies of ablated metal ions are found to be up to 8 eV while those of neutral species a re estimated to be less than 1.0 eV. The ablation yields of ablated sp ecies increase with increasing of laser fluence while the kinetic ener gies of ionic species are nearly independent of laser fluence. Possibl e mechanism of laser ablation of a Pr0.67Sr0.33MnO3 target is discusse d. (C) 1998 Elsevier Science B.V. All rights reserved.