Particular Case of Sr2FeMoO6

This chapter focuses on manganite thin films, but it is also interesting to present the results on the ordered double per-ovskite Sr2FeMoO6, even though it does not contain Mn, since it exhibits magnetoresistance [62] with a Curie temperature above 370 K. Films of Sr2FeMoO6-), were grown using pulsed laser deposition on (001)-SrTi03 [63,64]. They are grown on both (001)- and (111)-SrTiO3 but in a narrow window near 900 °C and 10-6 Torr [65]. Asano et al. [63] have shown that by altering the growth conditions they are able to induce either positive (35%) or negative (-3%) magnetoresistance at 5 K under a magnetic field of 8 T. The films show metallic conductivity with a ferromagnetic transition above 400 K [65]. The experimental magnetic moment is calculated to be 4^b per formula unit [64], in agreement with the theoretical one [62]. Sr2FeMoO6 films also exhibit both an electronlike ordinary Hall effect and a holelike anomalous Hall contribution [66]. More importantly, an intergrain tunnelingtype low field magnetoresistance [67], even at room temperature [65, 68], has been reported.

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