Ž . Thin Solid Films 323 1998 178–182 Nanomechanic properties of epitaxial a-Fe films grown on ž / ž / CaF 111 rSi 111 2 N. Mattoso a, ) , D.H. Mosca a , W.H. Schreiner a , C.M. Lepienski b , I. Mazzaro c , S.R. Teixeira d a Lab. de Materiais, Depto. de Fısica, UFPR, Caixa Postal 19081, 81531-990 Curitiba, Brazil ´ b Lab. de Propriedades Nanomecanicas, Depto. de Fısica, UFPR, Caixa Postal 19081, 81531-990 Curitiba, Brazil ˆ ´ c ´ Lab. de Otica de Raios X e Instrumentac ¸ao, Depto. de Fısica, UFPR, Caixa Postal 19081, 81531-990 Curitiba, Brazil ˜ ´ d Lab. de Filmes Finos, Inst. de Fısica, UFRGS, Caixa Postal 15051, 91501-970 Porto Alegre, Brazil ´ Received 3 June 1997; accepted 14 November 1997 Abstract In this paper, we study the correlation between crystalline structure and nanomechanic properties of iron thin films grown on Ž . Ž . CaF 111 rSi 111 as a function of deposition temperature. The results show a dependence of in-plane residual strain with hardness and 2 nanoscratch measurements. The nanoindentation results show an increase of staircase behavior upon increasing deposition temperature, indicating a correlation of film crystal quality with mechanical behavior. From a structural point of view, Fe films deposited at 4508C are of the best quality. The biggest nanoscratch resistance was shown by a sample deposited at 1508C, which has larger hardness and better adhesion. q 1998 Elsevier Science S.A. All rights reserved. Keywords: Crystalline structure; Nanomechanic properties; Nanoindentation; Epitaxial a-Fe 1. Introduction Epitaxial magnetic thin films integrated on silicon wafers have been long overlooked despite the several magnetic devices which could be idealized in magnetic wx filmrsemiconductor systems 1 . Besides specific magnetic properties, the need for adherent and low stress thin films is fundamental. In the last years, several studies have been presented about nanoindentation and nanoscratch test in wx thin films 2 , indicating that the understanding of the nanomechanic properties in thin films is attracting great interest. The growth of Fe films on insulator or semiconductor wx substrates has been reported for FerGaAs 3 , FerZnSe wx wx wx 4 , FerSi 5 and FerMgO systems 6 . Unfortunately, reports of Fe films grown on CaF are rare. Recently, Hein 2 wx et al. 7 have shown that the nucleation process of Fe on Ž . CaF rSi 111 occurs by island growth. More recently, we 2 have shown the influence of the deposition temperature on crystalline structure and strain of Fe films grown on Ž . Ž . wx CaF 111 rSi 111 8 . Particularly, we have shown that 2 ) Corresponding author. Ž . Fe films grown at 4508C on CaF 111 show excellent 2 structural quality growing epitaxially and exhibiting the Nishiyama–Wassermann epitaxial relationship. In this article, we show the importance of deposition temperature on microstructural aspects and on the hardness and adhesion of epitaxial Fe films grown on Ž . Ž . CaF 111 rSi 111 . 2 2. Experimental The epitaxial 40 nm CaF buffer layers were deposited 2 Ž . on commercial Si 111 wafers which were cleaned and deoxidized immediately before the vacuum chamber load- ing in HF. Thermal evaporation of the fluoride was accom- plished from a tungsten boat at a rate of 0.1 nm s y1 . The Ž . wafers were originally cut with a 2.58 tilt of the 111 w x plane relative to normal towards the 110 direction. We used a BALZERS UMS 500P e-beam system with a base pressure of 2 = 10 y6 Pa. The buffer layers were deposited with intentional thermocouple-controlled heating of the substrate to 3008C using a halogen lamp. Immediately after deposition, the layers were annealed while in situ at 10008C 0040-6090r98r$19.00 q 1998 Elsevier Science S.A. All rights reserved.