Enhancement of [00l] Texture and Magnetoresistance of Sputtered La–Ca–Mn–O Thin Films on Silicon by Inserting Buffer Layers

Abstract

Highly [00l] textured La–Ca–Mn–O films grown by RF sputtering on thermally oxidized amorphous SiO2-buffered and sputtered LaNiO3-buffered Si(100) were studied. The [00l] texture was the highest, and the maximum MR was 700% at substrate temperature 700°C for the buffer scheme La–Ca–Mn–O/SiO2/Si. Post annealing apparently deteriorated the optimal texture and reduced MR effect of the SiO2-buffered La–Ca–Mn–O film. MR effect of highly [00l] textured La–Ca–Mn–O film on LaNiO3 buffered silicon could not be examined because of shunting by the low resistivity LaNiO3 buffer layer. Low conductivity buffer-layer such as LaAlO3 and/or SrTiO3 were adopted between LaNiO3 and La–Ca–Mn–O film. 176% MR was manifested for a post-annealed La–Ca–Mn–O/LaAlO3/LaNiO3/Si buffer scheme.