Anomalous Hall effect in Fe/Gd bilayers

¹  Department of Physis and Institute of Nanoscience & Technology, The Hong Kong University of Science and Technology (HKUST) - Clear Water Bay, Kowloon, Hong Kong, PRC
² Image-characterization Core Lab, Research and Development, 4700 King Abdullah University of Science and Technology (KAUST) - Thuwal 23900-6900, Kingdom of Saudi Arabia
³  Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University Beijing 100084, PRC
⁴  School of Materials Science and Engineering, Beihang University - Beijing 100191, PRC

Corresponding author: Xixiang.Zhang@kaust.edu.sa

Received: 17 February 2010
Accepted: 7 April 2010

Abstract

Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films.