Delayed release of Li atoms from laser ablated lithium niobate

The present vapor-phase optical (atomic) absorption measurements study the escape dynamics of Li atoms from a LiNbO3 target surface upon laser ablatio n in vacuum. The objective is to understand the low-Li content of LiNbO3 fi lms prepared by pulsed laser deposition. A primary result is a delayed rele ase of Li atoms, 2-20 mu s after the laser pulse; they eject with a velocit y of 6x10(5) cm s(-1), which is consistent with an electronic ejection mech anism. The long emission period means there are almost no intraplume Li col lisions in the gas phase and no forward focusing of the delayed released at oms. This appears to explain the low-Li content usually found in films grow n in the normal direction. (C) 2000 American Institute of Physics. [S0003-6 951(00)04605-2].