Spin reorientation in single-crystal CoFe2O4 thin films

• Published in: Journal of physics. Condensed matter Vol. 17; no. 8; pp. 1399 - 1404
• Main Authors: Lisfi, A, Williams, C M, Johnson, A, Nguyen, L T, Lodder, J C, Corcoran, H, Chang, P, Morgan, W
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 02.03.2005; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Physics; Annealing; Inorganic compounds; Cobalt oxides; Pulsed laser deposition; Spin reorientation; Thin films; Magnetization direction; Tensile stress; Monocrystals; Magnetic anisotropy; Stress effects; Iron oxides; Perpendicular magnetic anisotropy
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/17/8/018

Reorientation of magnetic anisotropy has been observed in single-crystal CoFe2O4 thin films deposited on (100) MgO substrate by pulsed laser deposition (PLD). The as-grown film exhibits a perpendicular anisotropy whereas after annealing the magnetization easy axis switches to be parallel to the film plane. The origin of such spin reorientation is explained in terms of competition between stress and magnetocrystalline anisotropies. The as-prepared film is under tensile stress, which induces a huge perpendicular uniaxial anisotropy dominating the in-plane magnetocrystalline component. Annealing releases the stress by relaxing the film lattice. Consequently, the perpendicular stress anisotropy is considerably reduced and magnetocrystalline anisotropy prevails, leading to an in-plane alignment of the easy axis.