Coexistence of large positive and negative magnetoresistance in Cr2Si2Te6 ferromagnetic semiconductor

Abstract

Magnetoresistance (MR) phenomenon couples the electron transport with magnetic field, which has been at the forefront of condensed matter physics and materials science. Large-MR behaviors are of particularly importance for magnetic sensor and information memory applications, and their scarcity has aroused intensive research. Moreover, due to the different physical origins, combination of large positive and negative MR (pMR and nMR) in one single compound has rarely been reported. In present work, we achieved a coexistence of large pMR and nMR in Cr 2 Si 2 Te 6 ferromagnetic semiconductor single crystal with different field configurations. Specifically, a large nMR of about −60% was obtained under the in-plane field, while a large pMR higher than 1000% took over in the out-of-plane direction. We attribute this field direction-sensitive dualistic large MR behavior to the competition and cooperation effect from the ferromagnetic interaction, orbital scattering and electronic correlation that coexist in Cr 2 Si 2 Te 6 , which contribute to nMR, pMR, and nMR, respectively, in dominated temperature and field ranges, and show different weights under different field directions. The elucidated multiple MR mechanism in this ferromagnetic semiconductor will shed light on the pursuit of coexistence of large pMR and nMR for field-sensitive device applications.

Abnormal thickness-dependent magneto-transport properties of vdW magnetic semiconductor Cr2Si2Te6

“…The CST bulk crystal results will be discussed rst. The EDS analysis spectrum and average chemical ratio (Cr: Si: Te = 18: 21: 60) of the platelet indicates that the content of Cr is slightly smaller than in previous reports 27,28 . Some Cr atoms are replaced by Si or Te, but the stoichiometry is near ideal for CST.…”

“…In thick CST akes (thickness more than 100 nm), the MR ratio increases with increasing magnetic eld and maintains a positive value. Although the ferromagnetic interaction and long-range ferromagnetic ordering in CST normally give NMR behavior, the total magnetoresistance effect always has other effects involved including orbit scattering, electron-electron correlation, and so on 27 . It indicates that even below T c there is still more than one effect contributing to the resistivity change.…”

“…The slightly different content of elements also brings differences in transport properties. CST crystals normally shows insulating behavior with ultra-large resistance of about 10 9 ohms at liquid helium temperature 27 . However, our self-growth crystals have resistances of less than 0.2 ohms under the same conditions, indicating semiconductor behavior.…”

“…It has perpendicular magnetic anisotropy, temperature-dependent magnetic ordering, and a unique Ising spin model that is different to Cr 2 Ge 2 Te 6 . The controversial magnetotransport results in CST single crystals are still under debate, 27,28 and there are no relevant reports based on the magneto-electric properties and spintronic applications of its nano akes.…”

Mechanism‐based tuning of room‐temperature ferromagnetism in Mn‐doped β‐Ga2O3 by annealing atmosphere

“…Owing to the coexistence of charge and spin degrees of freedom in the diluted magnetic semiconductors, tremendous attention has been aroused in semiconductor spintronics. [1][2][3][4] As a promising wide-bandgap material that has been studied for a long time for various applications, including solar-blind detectors and high-frequency power devices, 5,6 very recently gallium oxide (Ga 2 O 3 ) has attracted much interest for its potentials in spintronic applications. [7][8][9][10] It is found that the ferromagnetism (FM) in Ga 2 O 3 can be realized by doping with various metallic elements, such as Fe, 11 Ni, 12 Cr, 13 Sn, 14 and Mn.…”