Perpendicular magnetic anisotropy and its electric field effect in Co ultrathin films deposited directly on SrTiO3(111) surface. (7th November 2018)

• Record Type: Journal Article
• Authors: Nakazawa, Shingo; Obinata, Aya; Chiba, Daichi; Ueno, Kazunori
• Is Part Of: Japanese journal of applied physics. Volume 57:Number 12(2018)
• Publication Date: 2018-11-07
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.57.123001
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We have investigated magnetic anisotropy and its electric field effect in ultrathin Co with a Pt cap layer. The layers were directly deposited on SrTiO3 (111) and (100) surfaces without any under layer. In as-deposited samples, a stronger perpendicular magnetic anisotropy was observed in the (111) sample. A back gate configuration was used to apply the electric field to the bottom surface of Co layer through the SrTiO3 substrate. In both samples, the coercivity was enhanced with a positive gate bias, which corresponds to the direction of the electron accumulation. The efficiency of the change in the coercivity per modulated electron density was greater in the (111) sample over a wide temperature range including 2 K, at which the thermally activated magnetization reversal was expected to be suppressed. The results suggest that the surface orientation of the substrate affects both the magnetic anisotropy and its electric field effect on Co.