EuTe is a magnetic semiconductor with potential applications in prototype optoelectronic and spintronic devices. In this work, we investigated the structural properties of EuTe grown on BaF2(111) substrates by molecular beam epitaxy. X-ray diffraction measurements were performed on two series of samples with different growth times and temperatures. The growth occurs in the Volmer-Webber mode, with initial formation of islands that then coalesce to form thin films. The islands size, mosaic spread, and strain state are deduced as a function of growth conditions. Surprisingly, the EuTe islands exhibit in-plane tensile strain, while compressive strain is expected for structures grown over a substrate with smaller lattice parameter. The islands tensile strain relaxes with increasing deposition times and substrate temperature, and it tends to zero for thick EuTe films. We propose that the EuTe/BaF2 lattice mismatch is compensated by the formation of interfacial misfit dislocations. The growth conditions out of equilibrium favor the formation of a metastable state with a high concentration of dislocations that over-compensates the original misfit. This is in agreement with the observed reduction of tensile strain as the substrate temperature increases. © 2013 Elsevier B.V.386 139145Masumoto, Y., Takagahara, T., (2002) Semiconductor Quantum Dots: Physics, Spectroscopy and Applications, , SpringerBader, S.D., Parkin, S.S.P., Spintronics (2010) Annual Review of Condensed Matter Physics, 1, pp. 71-88Mauger, A., Godart, C., The magnetic, optical, and transport properties of representatives of a class of magnetic semiconductors: The europium chalcogenides (1986) Physics Reports, 141, pp. 51-176Schmutz, L.E., Dresselhaus, G., Dresselhaus, M.S., Optical absorption of EuTe in high magnetic fields (1978) Solid State Communications, 28, pp. 597-600Battles, J.W., Everett, G.E., Antiferromagnetic-Resonance Measurements in Europium Telluride (1970) Physical Review B, 1, p. 3021Nolting, W., Mathi Jaya, S., Rex, S., Magnetic polaron in ferro- and antiferromagnetic semiconductors (1996) Physical Review B, 54, p. 14455Heiss, W., Kirchschlager, R., Springholz, G., Chen, Z., Debnath, M., Oka, Y., Magnetic polaron induced near-band-gap luminescence in epitaxial EuTe (2004) Physical Review B, 70, p. 035209Heiss, W., Prechtl, G., Springholz, G., Giant tunability of exciton photoluminescence emission in antiferromagnetic EuTe (2001) Physical Review B, 63, p. 165323Ishida, A., Veis, M., Inoue, Y., Strong intersubband absorption in EuTe/PbTe double-well superlattices at normal incidence (2007) Japanese Journal of Applied Physics Part 2-Letters and Express Letters, 46, pp. 281-L283Hernandez, F.G.G., Henriques, A.B., Rappl, P.H.O., Abramof, E., Magnetic field induced near-band-gap optical properties in EuTe layers (2009) International Journal of Modern Physics B, 23, pp. 2999-3003Kaminski, B., Lafrentz, M., Pisarev, R.V., Yakovlev, D.R., Pavlov, V.V., Lukoshkin, V.A., Henriques, A.B., Bayer, M., Spin-induced optical second harmonic generation in the centrosymmetric magnetic semiconductors EuTe and EuSe (2009) Physical Review Letters, 103Heredia, E., Motisuke, P., Rappl D. H P, O., Brasil, M.J.S.P., Iikawa, F., High energy sideband on the magnetic polaron related luminescence in EuTe (2012) Applied Physics Letters, 101, p. 092108. , 10.1063/1.4748981Díaz, B., Malachias, A., Rappl, P.H.O., Abramof, E., Chitta, V.A., Henriques, A.B., Growth of EuTe islands on SnTe by molecular beam epitaxy (2010) Journal of Crystal Growth, 312, pp. 2828-2833Díaz, B., Malachias, A., Montoro, L.A., Rappl, P.H.O., Abramof, E., Vertically ordered magnetic EuTe quantum dots stacks on SnTe matrices (2012) Nanotechnology, 23, p. 015604Díaz, B., Granado, E., Abramof, E., Rappl, P.H.O., Chitta, V.A., Henriques, A.B., Magnetic resonant x-ray diffraction study of europium telluride (2008) Physical Review B, 78, p. 134423Söllinger, W., Heiss, W., Lechner, R.T., Rumpf, K., Granitzer, P., Krenn, H., Springholz, G., Exchange interactions in europium monochalcogenide magnetic semiconductors and their dependence on hydrostatic strain (2010) Physical Review B, 81, p. 155213Goncharenko, I.N., Mirebeau, I., Ferromagnetic interactions in EuS and EuSe studied by neutron diffraction at pressures up to 20.5 GPa (1998) Physical Review Letter, 80, pp. 1082-1085Kepa, H., Springholz, G., Giebultowicz, T.M., Goldman, K.I., Majkrzak, C.F., Kacman, P., Blinowski, J., Bauer, G., Magnetic interactions in EuTe epitaxial layers and EuTe/PbTe superlattices (2003) Physical Review B, 68, p. 024419Diaz, B., Granado, E., Abramof, E., Torres, L., Lechner, R.T., Springholz, G., Bauer, G., Magnetic ordering and transitions of EuSe studied by x-ray diffraction (2010) Physical Review B, 81, p. 184428Giles, C., Yokaichiya, F., Kycia, S.W., Sampaio, L.C., Ardiles-Saravia, D.C., Franco, M.K.K., Neuenschwander, R.T., High-resolution X-ray diffraction beamline at the LNLS for the study of charge, orbital and magnetic structures (2003) Journal of Synchrotron Radiation, 10, pp. 430-434Hohnke, D.K., Holloway, H., Hurley, M.D., Epitaxial lead chalcogenide films: Orientation on substrates with the fluoride structure (1976) Thin Solid Films, 38, pp. 49-55Malachias, A., Magalhães-Paniago, R., Neves, B.R.A., Rodrigues, W.N., Moreira, M.V.B., Pfannes, H.D., De Oliveira, A.G., Metzger, T.H., Direct observation of the coexistence of coherent and incoherent InAs self-assembled dots by x-ray scattering (2001) Applied Physics Letters, 79, p. 4342Renaud, G., Barbier, A., Robach, O., Growth, structure, and morphology of the Pd/MgO(001) interface: Epitaxial site and interfacial distance (1999) Physical Review B, 60, p. 5872Theiss, S.K., Chen, D.M., Golovchenko, J.A., Three-stage lattice relaxation of Ge islands on Si(111) measured by tunneling microscopy (1995) Applied Physics Letters, 66, pp. 448-450Vogt, J., Henning, J., Weiss, H., The structure of CaF2 (111) and BaF2 (111) single crystal surfaces: A tensor low energy electron diffraction study (2005) Surface Science, 578, pp. 57-70Braun, O.M., Kivshar, Y.S., (2004) The Frenkel-Kontorova Model: Concepts, Methods, and Applications, , SpringerFrank, F.C., Van Der Merwe, J.H., One-dimensional dislocations. I. Static theory (1949) Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 198, pp. 205-216Jesser, W.A., Van Der Merwe, J.H., The size dependence of equilibrium elastic strain in finite epitaxial islands (1972) Surface Science, 31, pp. 229-240Frank, N., Springholz, G., Bauer, G., Imaging of misfit dislocation formation in strained layer heteroepitaxy by ultrahigh vacuum scanning tunneling microscopy (1994) Physical Review Letters, 73, pp. 2236-2239Satapathy, D.K., Kaganer, V.M., Jenichen, B., Braun, W., Däweritz, L., Ploog, K.H., Periodic array of misfit dislocations at the MnAsâ̂GaAs interface studied by synchrotron x-ray diffraction (2005) Physical Review B, 72, p. 155303Milchev, A., Markov, I., The effect of realistic forces in finite epitaxial islands: Equilibrium structure, stability limits and substrate-induced dissociation of migrating clusters (1985) Surface Science, 156 (PART 1), pp. 392-403Ratsch, C., Zangwill, A., Equilibrium theory of the Stranski-Krastanov epitaxial morphology (1993) Surface Science, 293, pp. 123-131Jalkanen, J., Rossi, G., Trushin, O., Granato, E., Ala-Nissila, T., Ying, S.C., Stress release mechanisms for Cu on Pd(111) in the submonolayer and monolayer regimes (2010) Physical Review B, 81, p. 041412