Thickness dependence of the martensitic transformation in textured Cu-Al-Ni thin films grown by sputtering on Si (001).

M. MORÁN; A.M. CONDÓ; F. SOLDERA; M. SIRENA; N. HABERKORN

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Simposio; XXIII Simposio Latinoamericano de Física del Estado Sólido, SLAFES 2018; 2018

We study the thickness influence on the martensitic transformation in Cu-Al-Ni thin films grown by sputtering on Si (001). Thin films with thicknesses between 0.1 μm and 2.25 μm were grown at 563 K. The analysis of the microstructure reveals a columnar growth with preferred orientation Cu-Al-Ni L2_1 (001)[100]//Si (001)[100]. The martensitic transformation is strongly suppressed for films thinner than 1.3 μm, which can be related with an interfacial layer imposing restitutive forces. This is evidenced in the extended transformation / retransformation ranges and in the absence of hysteresis for 0.15 μm thick films.