Thermally stimulated solid state reactions in Fe-Al multilayers prepared by pulsed laser deposition

Two 15-period Fe-Al multilayers (single layer thicknesses similar to5 nm Ai and similar to2 nm Fe) prepared by direct and crossed-beam pulsed laser de position (DPLD and CBPLD, respectively) were subjected to annealing between 50 and 95 degreesC. phase analysis done by X-ray diffraction and determina tion of layer morphology using X-ray reflectometry showed that solid state reaction kinetics is different in DPLD and CBPLD samples. This applies in p articular to the sequence of intermetallic compounds formed as well as to t he temperatures of full intermixing. Pronounced interdiffusion of Fe and.-i l starts at annealing temperatures of about 110 -140 degreesC and a full in termixing of multilayer material occurs at temperatures between 250 degrees C (DPLD) and 300 degreesC (CBPLD). Tile difference in kinetics between CBPL D and DPLD samples is due to a difference in the structure of interfaces an d in their average chemical composition. (C) 2001 Elsevier Science B.V. All rights reserved.