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Stiffness Constant (stiffness + constant)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Spin-wave resonance and magnetization studies in La0.7Mn1.3O3 films

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003
P. Aleshkevych
Abstract Spin-wave resonance (SWR) in high quality epitaxial La0.7Mn1.3O3 films prepared by dc-magnetron sputtering was studied at a frequency of 9.25 GHz. SQUID magnetometry was used to study the film magnetization. A well-resolved structure of the SWR spectrum consists of surface and bulk spin waves modes. The experimentally found SWR spectra are in good agreement with the theory of SWR based on the surface-inhomogeneity model. Using the SWR and magnetization data, the spin-wave stiffness constant and the values of the bulk anisotropies were deduced. [source]

Photoinduced spin waves in Fe/AlGaAs (001) heterostructure

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 8 2008
H. B. Zhao
Abstract Photoinduced spin waves are investigated for Fe films on AlGaAs (001) using the time resolved magneto-optical Kerr effect. We observe first and second order standing spin waves as well as uniform magnetization precession. The anisotropy fields and exchange stiffness constant are obtained from the field and azimuthal dependence of the spin wave frequencies using the Landau-Lifshitz-Gilbert equation. A comparison with spin wave resonance measurements reveals a more pronounced interface effect on the low order standing spin waves in thin films. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Ab initio theory of exchange interactions in itinerant magnets

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003
I. Turek
Abstract The paper reviews an ab initio two-step procedure to determine thermodynamic properties of itinerant magnets. In the first step, the selfconsistent electronic structure of a system is calculated using the tight-binding linear muffin-tin orbital method combined with Green function techniques. In the second step, the parameters of the effective classical Heisenberg Hamiltonian are determined using the magnetic force theorem and they are employed in subsequent evaluation of magnon spectra, the spin-wave stiffness constants and the Curie/Néel temperatures. Applicability of the developed scheme is illustrated by investigations of selected properties of 3d metals Fe, Co, and Ni, diluted magnetic semiconductors (Ga,Mn)As, and 4f metals Gd and Eu. [source]

Elastic constants of aluminum nitride

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2007
M. Kazan
Abstract We report on the application of Brillouin spectroscopy as an approach to non-destructive optical characterization of the elastic constants of semiconductors with the wurtzite symmetry. Three different configurations were used to achieve a complete determination of the elastic stiffness constants of bulk AlN substrates grown by the Physical Vapor Transport (PVT) method. The scattering diagrams of these three configurations are presented showing the geometrical arrangements necessary to observe all the elastic stiffness constants for the partially nontransparent wurtzite type of the crystal structure. Because aluminum nitride (AlN) is a suitable material for the fabrication of light emitting devices, the characterization of its elastic constants was carried out very precisely to provide a reliable data which can be used for the determination of residual stress arising during the growth of AlN thin films or wide band gap semiconductor thin films on substrates of AlN. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]