11 research outputs found
Electromagnetic performances and main parameter sensitivity effect on unbalance magnetic flux in a New SingleâPhase FEFSM with segmental rotor
Three-phase field excitation flux switching motor (FEFSM) with salient rotor structure has been introduced with their advantages
of rotor easy temperature elimination and controllable FEC magnetic flux. Yet, the salient rotor structure is found to
lead a longer magnetic flux path between stator and rotor parts, producing a weak flux linkage along with low torque performances.
Hence, a new structure of single-phase FEFSM using segmental rotor with non-overlap windings is proposed with
advantages of shorter magnetic flux path, light weight and robust rotor structure. Analysis on fundamental magnetic flux
characteristics, armature and FEC magnetic flux linkages, cogging torque, back-Emf, various torque capabilities, refinement
of unbalance magnetic flux, and torque-power versus speed characteristics are conducted using 2D FEA through JMAG
Designer version 15. The results show that magnetic flux amplitude ratio has been improved by 41.2% while the highest
torque and power achieved are 1.45 Nm and 343.8 W, respectively
Anomalous electron-phonon coupling in kagome ferromagnetic Weyl semimetal CoSnS
We present results of a Raman scattering study of the Kagome ferromagnet
CoSnS, with a focus on electronic and phononic excitations and
their interplay. In addition, the electronic band structure is analyzed
theoretically, enabling a semi-quantitative explanation of the spectra. A
prominent feature in the electronic spectra is a redistribution of spectral
weight from low to high energies starting at the Curie temperature Tc. The
Raman intensity is suppressed below approximately 1000cm and increases
above to a peak at 2000 cm in all symmetries. Two Raman active phonon
modes are identified in A and E symmetry. The A phonon
couples strongly to the electronic continuum as indicated by the asymmetric
Fano-type line shape. The asymmetry depends non-monotonically on temperature
and is maximal close to the magnetic transition. In the limit the
phonon is nearly symmetric. The evolution of the coupling strength and the
electronic continuum as a function of temperature is attributed to a band
splitting induced by the ferromagnetic phase transition which substantially
reduces the DOS towards . The electrons of the Co atoms in the
crystal field modulated by the A phonon are implied to be a critical
component contributing to the strong electron-phonon coupling of that phonon.
These results allow a comprehensive understanding of the bulk band structure
evolution as a function of temperature in CoSnS, offering key
insights for further studies of the driving force behind the long-range
magnetic order and novel topological states in this compound.Comment: 9 pages, 4 figure