Peculiar temperature dependence of magneto-optic Kerr rotation associated with antiferromagnetic–paramagnetic transition. (1st March 2023)

• Record Type: Journal Article
• Authors: Ekawa, Hirofumi; Okano, Takashi; Huang, Oujin; Iino, Ion; Toyoki, Kentaro; Nakatani, Ryoichi; Kato, Takeshi; Shiratsuchi, Yu
• Is Part Of: Japanese journal of applied physics. Volume 62:Number SB(2023)
• Publication Date: 2023-03-01
• Subjects: magneto-optic Kerr effect -- antiferromagnet -- neel temperature; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/ac8b8e
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We investigate the magneto-optic Kerr effect in perpendicularly magnetized Pt/Co/Ir/Cr2 O3 /Pt thin films, associated with the antiferromagnetic–paramagnetic transition of the Cr2 O3 layer. The magneto-optic Kerr rotation angle ( θ K ) shows oscillatory behavior as a function of the photon energy of incident light owing to interference in the Cr2 O3 layer. The temperature dependence of θ K at 2.67 eV ( λ = 465 nm), at which the largest θ K is obtained, shows a sharp dip at 287.0 K. The dip temperature is similar to the reported Néel temperature for Cr2 O3 thin films. Although the θ K spectra measured at several temperatures are generally explained by the classical interference model, θ K is enhanced at 2.36–2.79 eV ( λ = 525–445 nm) close to the dip temperature. This peculiar enhancement in θ K is discussed on the basis of the anomaly in the optical parameters of the Cr2 O3 layer associated with the antiferromagnetic–paramagnetic transition.