Temperature dependence of the exchange bias properties in polycrystalline BiFeO3/Ni80Fe20

• Published in: 2015 IEEE Magnetics Conference (INTERMAG) p. 1
• Main Authors: Richy, J., Hauguel, T., Jay, J., Pogossian, S. P., Warot-Fonrose, B., Sheppard, C. J., Snyman, J. L., Strydom, A. M., Ben Youssef, J., Prinsloo, A. R., Spenato, D., Dekadjevi, D. T.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2015
• Subjects: Anisotropic magnetoresistance; Couplings; Magnetic hysteresis; Perpendicular magnetic anisotropy; Temperature dependence; Temperature measurement
• ISSN: 2150-4598; 2150-4601
• DOI: 10.1109/INTMAG.2015.7156544

In this study, we report a temperature dependent analysis of the exchange bias properties in BFO/Py bilayers as a function of the BFO thickness. The temperature dependence of the exchange bias field (H e ) and the coercive field (H c ) are first presented. To understand exchange bias magnetization reversal and the magnetic anisotropies, we will then present an azimuthal study of H e and H c at 300 K and 77 K. Finally, results of a controlled field cooling protocol applied on all samples will be discussed to understand anisotropy energy distribution. The bilayers were grown by radio-frequency sputter deposition, with the following structure: Si/Pt(14 nm)/BiFeO 3 (t BFO )/Ni 80 Fe 20 (10 nm)/ Pt(10 nm), with t BFO among 0 nm, 29 nm and 177 nm . To induce uniaxial anisotropy, a 300 Oe field H dep was applied during the growth . The XRD analysis confirmed a single polycrystalline structure for the BFO layer.