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Magnetotransport Anomaly in Room‐Temperature Ferrimagnetic NiCo 2 O 4 Thin Films
Author(s) -
Chen Xuegang,
Zhang Xiaozhe,
Han MyungGeun,
Zhang Le,
Zhu Yimei,
Xu Xiaoshan,
Hong Xia
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201805260
Subject(s) - condensed matter physics , ferrimagnetism , materials science , magnetoresistance , hall effect , spintronics , spinel , electrical resistivity and conductivity , ferromagnetism , magnetization , magnetic field , physics , quantum mechanics , metallurgy
The inverse spinel ferrimagnetic NiCo 2 O 4 presents a unique model system for studying the competing effects of crystalline fields, magnetic exchange, and various types of chemical and lattice disorder on the electronic and magnetic states. Here, magnetotransport anomalies in high‐quality epitaxial NiCo 2 O 4 thin films resulting from the complex energy landscape are reported. A strong out‐of‐plane magnetic anisotropy, linear magnetoresistance, and robust anomalous Hall effect above 300 K are observed in 5–30 unit cell NiCo 2 O 4 films. The anomalous Hall resistance exhibits a nonmonotonic temperature dependence that peaks around room temperature, and reverses its sign at low temperature in films thinner than 20 unit cells. The scaling relation between the anomalous Hall conductivity and longitudinal conductivity reveals the intricate interplay between the spin‐dependent impurity scattering, band intrinsic Berry phase effect, and electron correlation. This study provides important insights into the functional design of NiCo 2 O 4 for developing spinel‐based spintronic applications.