Dynamic origin of first and second order phase transitions in magnetization reversal of elliptical nanodots.

Journal Article · Sun Jun 01 00:00:00 EDT 2008 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.77.214402· OSTI ID:1002237

Montoncello, F; Giovannini, L; Nizzoli, F; Vavassori, P; Grimsditch, M; CNISM,; CNR-INFM,; Res Ctr, CIC nanoGUNE

We study the magnetization reversal in elliptical nanodots with the external field applied exactly along the minor (hard) axis. By varying the magnitude of the applied field, several first and second order transitions take place and the system proceeds through magnetic configurations characterized by different symmetry properties. The dynamical matrix method is used to calculate the spin excitations as function of the applied field. This model system allows us to investigate the relationship between the singularities of the magnetization, the presence of soft spin excitations, and the symmetry properties of the static and dynamic magnetization fields. Rules that govern the transitions are formulated.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); CNSIM
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 1002237
• Report Number(s): ANL/MSD/JA-68868; TRN: US201102%%672
• Journal Information: Phys. Rev. B, Vol. 77, Issue Jun. 2008
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
QUANTUM DOTS
PHASE TRANSFORMATIONS
MAGNETIZATION
ORIGIN
SPIN
SYMMETRY
ELLIPTICAL CONFIGURATION