engleski

Thin Films of Al-Nb Intermetallic Compounds

Thin films of AlxNb1-x (95 ≥ x ≥ 20), have been prepared by magnetron codeposition in the CMS-18 sputtering system at room temperature. The structure of the as-deposited films was examined by the XRD and the AlNb films were amorphous in the range of composition from 30% to 85% aluminum content. Al95Nb5, Al90Nb10 and Al20Nb80 films were nanocrystalline. For the purpose of examination of thermal stability the samples were deposited onto glass and alumina ceramics. Thermal stability and phase transformation of the Al-Nb amorphous and nanocrystalline films under isochronal conditions were examined by continuous in situ electrical resistance measurements in vacuum. Estimated values of ρ and α are in accordance with the Mooij correlation, and reflect typical properties of the amorphous alloys containing early transition metals. As determined by the XRD method, the first dominant component after phase transformation is the AlNb3 intermetallic compound for Nb-rich alloys and the Al3Nb intermetallic compound for Al-rich alloys. The rate of extraction of intermetallic phase is dependent on composition. Amorphous Al-Nb films with composition closer to stoichiometric ratio of intermetallic compounds exhibit lower crystallization temperatures.

thin films; intermetallic compounds; aluminum; niobium

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