Crystallization of glassy metal surfaces in Mg-Zn alloy determined by resonant photoacoustic detection

O.E.MARTÍNEZ; U. CROSSA ARCHIOPOLI; Y.CESA; N.MINGOLO

APPLIED PHYSICS. A - MATERIALS SCIENCE AND PROCESSING

Springer Verlag

Lugar: Berlin; Año: 2005 vol. 81 p. 1667 - 1674

0947-8396

ABSTRACT Amorphous layers in a Mg-based alloy are studied by a resonant photoacoustic technique. The technique is shown to provide information on the crystallization temperature of a thin amorphous layer when the sample is heated. This determination provides crucial information regarding thermal stability of the treated surface, not accessible by standard calorimetric techniques. The layer analyzed is tens of micrometers thick, produced by rapid melting by a pulsed electron gun and subsequent rapid cooling towards the substrate. It is shown that the signal from the photoacoustic detection arises mainly from the volume change during crystallization at about 390 K. The volume change due to the structural relaxation of the glass before crystallization is also detected. PACS 64.70.Pf; 78.20.Nv; 81.70.Cv