In situ determination of the anisotropy field in ferromagnetic films using magnetic susceptibility measurements by MOKE

• Published in: Journal of magnetism and magnetic materials Vol. 477; pp. 49 - 54
• Main Authors: Bartlett, A., Belanger, R., Amann, M., Venus, D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2019; Elsevier BV
• Subjects: Anisotropy; Bilayers; Ferromagnetic films; Ferromagnetic materials; in situ MOKE; Kerr magnetooptical effect; Magnetic anisotropies; Magnetic fields; Magnetic measurement; Magnetic permeability; Magnetic susceptibility; Magnetism; Thin films; Thin films; in situ MOKE; Magnetic anisotropies; Magnetic susceptibility
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2019.01.037

•In situ measurement of magnetic anisotropy using MOKE and a small applied field.•a.c. magnetic susceptibility using a field transverse to the easy axis.•Co/W(110) anisotropy constants comparable to torque magnetometry.•Sensitive method detects Néel temperature of thin CoO film on Co/W(110).
An alternate method of measuring anisotropy fields in thin film ferromagnets is demonstrated. The method relies on the magnetic susceptibility in a small a.c. magnetic field, measured in situ using the magneto-optic Kerr effect (MOKE), and will be useful in situations where more specialized apparatus are not conveniently available, or constraints discourage the use of a large, static magnetic field. The method is demonstrated for Co/W(110) films, where it yields anisotropy fields in agreement with previous studies using more conventional torque magnetometry. The sensitivity of the method is demonstrated using CoO/Co/W(110) bilayer films, where the anisotropy due to interfacial exchange coupling is detected and used to find the Néel temperature of the thin CoO layer.