Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userUnusual Field Dependence of Anomalous Hall Effect in Ta/TbFeCo
147
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Experimental studies of anomalous Hall effect are performed for thin filmed Ta/TbFeCo in a wide range of temperatures and magnetic fields up to 3 T. While far from the compensation temperature (TM=277 K) the field dependence has a conventional shape of a single hysteresis loop, just below the compensation point the dependence is anomalous having the shape of a triple hysteresis. To understand this behavior, we experimentally reveal the magnetic phase diagram and theoretically analyze it in terms of spin-reorientation phase transitions. We show that one should expect anomalous hysteresis loops below the compensation point if in the vicinity of it the magnetic anisotropy is dominated by FeCo sublattice due to interaction with Ta.
rate research
Read More
The spin Hall magnetoresistance (SMR) and anomalous Hall effect (AHE) are observed in a Cr2O3/Ta structure. The structural and surface morphology of Cr2O3/Ta bilayers have been investigated. Temperature dependence of longitudinal and transverse resistances measurements confirm the relationship between SMR and AHE signals in Cr2O3/Ta structure. By means of temperature dependent magnetoresistance measurements, the physical origin of SMR in the Cr2O3/Ta structure is revealed, and the contribution to the SMR from the spin current generated by AHE has been proved. The so-called boundary magnetization due to the bulk antiferromagnetic order in Cr2O3 film may be responsible for the relationship of SMR and AHE in the Cr2O3/Ta bilayer.
The anomalous Hall effect in metal-insulator-semiconductor structures having thin (Ga,Mn)As layers as a channel has been studied in a wide range of Mn and hole densities changed by the gate electric field. Strong and unanticipated temperature dependence, including a change of sign, of the anomalous Hall conductance $sigma_{xy}$ has been found in samples with the highest Curie temperatures. For more disordered channels, the scaling relation between $sigma_{xy}$ and $sigma_{xx}$, similar to the one observed previously for thicker samples, is recovered.
A short review paper for the quantum anomalous Hall effect. A substantially extended one is published as Adv. Phys. 64, 227 (2015).
The origin of anomalous Hall effect (AHE) in ferromagnetic metallic glasses (MGs) is not yet understood completely. Here, the AHE is explored in Fe78Si9B13 MGs. We find the behavior of resistivity at low temperature seems to be more likely due to structure effect rather than Kondo-type effect. More importantly, we firstly find the primitive experiment anomalous Hall conductivity ({sigma}AH) without separation of extrinsic contribution has a linear magnetization (Mz) dependence when temperature is changing, which is another feature of intrinsic mechanism and indicates intrinsic contribution is dominated. Furthermore, the {sigma}AH normalized by Mz is independent of longitudinal conductivity ({sigma}xx), which shows the characteristic of dissipationless intrinsic mechanism. We suggest the intrinsic contribution can be understood from the density of Berry curvature integrated over occupied energies proposed for aperiodic materials recently, and the linear magnetization dependence can be understood qualitatively from the fluctuations of spin orientation and the proportional relationship between Berry curvature and magnetization. Moreover, based on the recent theory report of topological amorphous metals, we make a prediction that the large intrinsic {sigma}AH (616 S/cm) in Fe78Si9B13 MGs implies some topological properties of MGs waiting for further discovery.
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.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
