Epitaxial GdTiO3 / SrTiO3 structures with different SrTiO3 layer thicknesses are grown on (001) (LaAlO3) 0.3 (Sr2 AlTaO6) 0.7 substrate surfaces by hybrid molecular beam epitaxy. It is shown that the formation of the pyrochlore (Gd2 Ti2 O7) phase can be avoided if GdTiO 3 is grown by shuttered growth, supplying alternating monolayer doses of Gd and of the metalorganic precursor that supplies both Ti and O. Phase-pure GdTiO3 films grown by this approach exhibit magnetic ordering with a Curie temperature of 30 K. The electrical transport characteristics can be understood as being dominated by a conductive interface layer within the SrTiO3.
Bibliographical noteFunding Information:
P.M. and J.Y.Z. were supported through awards from the U.S. National Science Foundation (Grant No. DMR-1006640) and DOE Basic Energy Sciences (Grant No. DE-FG02-02ER45994). S.S. and S.J.A. acknowledge support through a MURI program of the Army Research Office (Grant No. W911-NF-09-1-0398). B.J. is supported by the MRSEC Program of the National Science Foundation (Award No. DMR 05-20415). The work made use of the UCSB Nanofabrication Facility, a part of the NSF-funded NNIN network.