Highlights

Composition Studies of Novel Oxides for Spintronics

Scientific Achievement

In this study, I investigate polycrystalline samples of SrRu_1-xTM_xO₃, where TM (transition metal) = Cr, Mn synthesized by a conventional solid state reaction method.  I compare the magnetic and compositional properties of these samples to SrRu_1-xTM_xO₃ thin-films (TM = Cr, Fe) fabricated by a pulsed laser deposition technique.

I have verified the composition of the synthesized materials.  The cation ratio in this material was determined by energy dispersive x-ray spectroscopy (EDXS) analysis in a Hitachi S-4700-II scanning electron microscope.  The effective Ru to Sr and TM to Sr ratios were determined and compared to the nominal Ru and TM contents in the SrRu_1-xTM_xO₃ formula: 1-x and x, respectively.  Magnetic properties were studied on thin films grown on SrTiO₃ substrate while EDXS was also performed on thin films simultaneously grown on LaAlO₃ to avoid the addition of the Sr peak from the substrate in the EDXS intensity spectra.

Significance

My EDXS results on polycrystalline SrRu_1-xTM_xO₃ show that the determined effective cation contents usually agree with the nominal values.  The Ru deficiency is present in most of the studied thin films on LaAlO₃, although this low effective Ru content is not reflected by much lower T_C values if directly referred to bulk SrRu_1-vO₃.  The same films, grown simultaneously on SrTiO₃ show much lower Ru deficiency. This work demonstrates that the selection of substrate for EDXS experiments on thin films may strongly affect the results.  This work has been published in Microsc. Microanal. 13 (Supp. 2), 624-625 (2007).

Performers

S. Kolesnik (Northern Illinois U.; Argonne-MSD)