Epitaxial growth of electron doped double perovskites LaxA2-xCrWO6 with A=Sr and Ca

Ferrimagnetic double perovskites are interesting for tunnel magnetoresistance (TMR) devices due to their high Curie-temperature and their half-metallicity. Because of the preferential formation of LaCrO3, the synthesis of bulk samples of electron-doped LaxSr2-xCrWO6 is difficult. However, due to the non-equilibrium growth conditions during pulsed laser deposition (PLD), the material can be grown as high-quality epitaxial film. We report the growth parameters of the compound LaxSr2-xCrWO6 on SrTiO3 substrates. Using reflection high-energy electron diffraction (RHEED) a layer-by-layer growth over the whole film thickness has been observed. Ca2CrWO6 grown on NdGaO3 has worse crystalline quality and shows paramagnetic behavior.