engleski

INVESTIGATION OF THERMAL STABILITY OF Al-Mo THIN FILMS

We have investigated AlxMo100-x 400 nm thin films (x ≤ 40 ≤ 90 in steps of 5 at%) prepared by magnetron sputtering on glass, alumina and quartz substrate. Deposited films are amorphous for 45 ≤ x ≤ 85. In comparison to other amorphous alloys of Al-refractory metals, alloys around Al75Mo25 composition exhibit high resistivities of the order of 1000 μΩcm. The thermal stability and crystallization of the amorphous samples were determined by the resistivity changes upon the isochronal heating and the results were complemented by GIXRD analysis for selected heating temperatures. Temperatures of crystallization are in the interval 450-650 oC and do not depend on the substrate. After the crystallization, the resistivity for x = 80, 75, 70 increases, contrary to the expectations, two to three times, and a reproducible exponential term in resistivity, reminiscent of the „hopping conductivity“ at lower temperatures appears. This „hopping“ term decreases by further heating the samples to higher temperatures (750 oC - 800 oC). GIXRD results do not indicate significant changes, like new phases. Only grain growth of the observed phases from 5 nm - 10 nm to 10 nm - 15 nm has been detected. Therefore, nanocrystalline Al-Mo thin films may present novel nanostructured materials with as yet undetermined properties.

Al-Mo; thin films; thermal stability

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