Epitaxial thin films of (Bi0.9La0.1)2NiMnO6 obtained by pulsed laser deposition

Bulk Bi2NiMnO6 has been shown to be ferromagnetic and ferroelectric. Here, we report a systematic study of the influence of the deposition conditions on the growth of (Bi0.9La0.1)2NiMnO6 thin films onto (0 0 1) SrTiO3 substrates by pulsed laser deposition. Oxygen pressure and substrate temperature have been varied from 0.3 to 0.6 mbar and 600 to 660 °C, respectively. Whereas it is found that single-phase and epitaxial films can be obtained in a relatively broad oxygen pressure range, the temperature window, centred on 620 °C, is extremely narrow. Films of low roughness, about 1 unit cell, have been obtained. It is found that the magnetisation of the films, which are ferromagnetic with Curie temperatures about 100 K, is lower than the expected theoretical value, which might be attributed to an incomplete Ni–O–Mn long-range ordering.