Ion-beam-induced atomic transport and phase formation in the system nickel/antimony

Abstract

Sb/Ni multilayers of 200 nm total thickness were ion-beam mixed with 900 keV Xe++ or 600 keV Ar++ ions using fluences up to 1016 ions/cm2. The formation of crystalline intermetallic phases was observed by X-ray diffraction (XRD). To investigate, on a microscopic scale, the mixing-effects the perturbed angular correlation (PAC) technique was applied using some 1012 implanted radioactive 111In ions. The different phases were identified in the PAC spectra by comparison with those taken for single-phase material of intermetallic Ni/Sb compounds and pure Ni and Sb. After the 111In implantation usually up to 50% of the probes are found with PAC-parameters typical for the single metallic layers. The rest of the probes showed a complex mixture of electric field gradients (EFG). During ion-beam mixing this fraction increased to 100%. In some experiments individual EFGs were resolved indicating the formation of crystalline NiSb and Ni5Sb2 intermetallic phases.