By the methods of transmission electron microscopy the phase, substructural and orientational transformations during the pulse photon treatment (PPT) by xenon lamp irradiation of the heterostructures Pt(25nm) – Ni(20nm)- Si(111) (0.38mm)- Ni(20nm)- Pt(25nm) has been made. The heterostructures were irradiated only from one side. The irradiation energy density (Ep) was 185, 215, 230, 245 and 285 J•cm-2. The results of the phase analysis for the silicides formed during the PPT of the heterosystems are presented in the table:
Ep (J•cm-2),irradiated side, non-irradiated side;
185, Ni1-yPtySi – Pt1-xNixSi – (Pt-Ni)2Si, (Pt-Ni)2Si;
215, Ni1-yPtySi – Pt1-xNixSi, Ni1-yPtySi – Pt1-xNixSi;
230, Pt1-xNixSi, Ni1-yPtySi – Pt1-xNixSi;
245, Pt1-xNixSi, Ni1-yPtySi – Pt1-xNixSi;
285, Pt1-xNixSi, Pt1-xNixSi.
On the non-irradiated side the silicides and the heterostructures, corresponding to the higher reaction temperature, are formed. The temperature effect of the irradiation is about 150°.
The silicide heterostructures are in epitaxial orientation, according to the relationship
(010),[100] Pt1-xNixSi (Ni1-yPtySi, PtNiSi) || (111),[11-2], [1-21] and [-211] Si.
The high degree dispersion for the silicide heterostructures is provided by the three symmetrically equivalent positions. The conjugation Ni1-yPtySi-Pt1-xNixSi on the interphase boundary is partially coherent, with the period of the misfit dislocation arrays of about 150nm and the Burgers vectors of the type [100] or <301>. The final silicide Pt1-xNixSi has no preferential orientation and has a large-block (as large as 2µm) structure. By the change of the Pt1-xNixSi lattice parameters the conclusion about the Ni-content increase with the Ep has been made.
The work was performed under the grant of Russian Foundation for Basic Research No. 06-03-96503-r-tsentr-ofi.
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