Surface structure of a binary alloy in different states of order: The transformation between the amorphous and the crystalline phase

Amorphous $\rm Pd_{81}Si_{19}$ is studied by scanning tunneling microscopy before and after crystallization, and after additional laser-quenching. Distances between structural units on the amorphous surface are comparable to lattice spacings on the crystallized sample indicating partial preservation of the local structure during the phase transformation. After laser-quenching the crystallized sample, the surface structure is similar to that of the initial amorphous state proving on the nm scale the successful transformation of the surface layers back into the amorphous state