ION-BEAM-INDUCED ATOMIC TRANSPORT AND PHASE-FORMATION IN THE SYSTEM NICKEL ANTIMONY .2. PHASE-FORMATION IN MIXED MULTILAYERS OBSERVED BY XRD AND PAC

Sb/Ni multilayers of 200 nm total thickness were ion-beam mixed with 9 00 keV Xe++ or 600 keV Ar++ ions using fluences up to 10(16) ions/cm2. The formation of crystalline intermetallic phases was observed by X-r ay diffraction (XRD). To investigate. on a microscopic scale, the mixi ng-effects the perturbed angular correlation (PAC) technique was appli ed using some 10(12) implanted radioactive In-111 ions. The different phases were identified in the PAC spectra by comparison with those tak en for single-phase material of intermetallic Ni/Sb compounds and pure Ni and Sb. After the In-111 implantation usually up to 50% of the pro bes are found with PAC-parameters typical for the single metallic laye rs. 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 fo rmation of crystalline NiSb and Ni5Sb2 intermetallic phases.