With the discovery of high entropy oxides in 2015 many different oxides have been synthesized using the high entropy strategy [1]. Since 2018 many different high entropy perovskites have been synthesized, some of them contain five elements on the A- or the B-site [2]. Some high entropy perovskites were synthesized with ten different elements, five on the A-site and five on the B-site [2]. Most of them were produced as polycrystalline powders, only a few oft them have been grown as thin film [2-5]. In the recent research, the focus has shifted to high entropy manganites-perovskites, because of their interesting magnetic properties. One high entropy manganite-perovskite is (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ which was previously produced as a powder [2].
We have grown thin films of (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ via pulsed laser deposition on two different substrates, one with a cubic structure SrTiO₃ (001) and one with an orthorhombic structure NdGaO₃ (001). X-ray diffraction data confirmed epitaxial growth of (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ on both substrates. Wide-range reciprocal space mapping and electron-backscattered diffraction revealed, that (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ has three different crystalographic orientations on SrTiO₃ and two on NdGaO₃. On SrTiO₃ (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ grows in two different directions (001) and (110). The (001) orientated crystals are rotated by 45° with respect to the substrate, while the (110) crystals are aligned either to the substrate lattice or rotated by 45°. On NdGaO₃ we observed only (001) orientated crystals, but with two different in-plane orientations, either (001) or (110). High-resolution transmission electron microscopy confirmed a long-range ordered lattice with a short-range chemical disorder. Zero-field-cooled and field-cooled measurements revealed a magnetic transition temperature around 38 K for (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ grown on SrTiO₃, which is lower compared to most of the parent compounds. This is in good agreement with the magnetic measurements on corresponding powder.
[1] C. M. Rost et. al., Nat. Commun. 6, 8485 (2015).
[2] A. Sarkar et. al., J. Eur. Ceram. Soc. 38, 2318 (2018).
[3] R. Das et. al., Phys. Rev. Mater. 7, 024411 (2023).
[4] A. Sarkar et. al., Adv. Mater. 35, 2207436 (2023).
[5] A. R. Mazza et. al., Phys. Rev. B 104, 094204 (2021).