Interrelation Between the Structural, Magnetic and Magnetoresistive Properties of Double-Perovskite Sr2FeMoO6−δ Thin Films

• Published in: Journal of electronic materials 2016-07, Vol.45 (7), p.3466-3472
• Main Authors: Kalanda, N. A., Demyanov, S. E., Petrov, A. V., Karpinsky, D. V., Yarmolich, M. V., Oh, S. K., Yu, S. C., Kim, D.-H.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Materials Science; Optical and Electronic Materials; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-016-4478-5

Investigations of the formation conditions of Sr 2 FeMoO 6−δ compound films, depending on the substrate temperature and sputtering rate with their subsequent thermal treatment, have made it possible to obtain the single-phase homogeneous films. The analysis of x-ray diffractometry and magnetic force microscopy data has made it possible to reveal the superstructural ordering of Fe and Mo cations, determine the spin polarization degree of conduction electrons and magnetic structure of the films. Studies of temperature and magnetic field dependences of magnetization in the zero-field cooling and field-cooling modes have shown the existence of magnetic regions with low coercitive force, which bears witness of the domination of the ferrimagnetic state at temperatures above the blocking temperature. Lower than this temperature, the nanosized grains are present, where homogeneous magnetization promotes the realization of a superparamagnetic state, which is “obscured” at the higher temperatures. The negative magnetoresistive effect, reaching 14% at low temperatures in a magnetic field of 8 T, is by its nature the giant magnetoresistance with monodirectional spin-polarized electrons.