What is a anisotropy field?
The anisotropy field represents the hypothetical field that would be able to align the magnetization perpendicular to the easy direction, the c-axis. It is defined by H a = 2 K 1 / J s 0 , where the anisotropy constant characterizes the associated anisotropy energy.
What is magnetic anisotropy field?
Magnetic anisotropy is the property that confers a preferred direction on the spin of a system which may not be aligned with an external magnetic field, as promoted by the Zeeman effect.
What is difference between FMR and EPR?
The FMR occurs at high field values while EPR occurs at low magnetic field values. Also, line-width of ferromagnetic materials is large according to paramagnetic materials. Exchange interaction energy between unpaired electron spins that contribute to the ferromagnetism causes the line narrowing.
How are anisotropy fields measured?
The usual method for anisotropy determinations is torque magnetometry, which directly measures the macroscopic torque exerted by an applied field on the magnetization of a sample that is not precisely aligned with the field.
What is anisotropy and isotropy?
isotropic: Properties of a material are identical in all directions. anisotropic: Properties of a material depend on the direction; for example, wood. In a piece of wood, you can see lines going in one direction; this direction is referred to as “with the grain”.
How do you calculate anisotropy?
For anisotropy images, the parallel (III) and perpendicular (I⊥) components of the emitted light (with respect to polarized excitation) are simultaneously acquired and used to calculate the steady state fluorescence anisotropy as r = (III − I⊥)/(III + 2I⊥).
What is FMR frequency?
FMR is usually measured at microwave frequencies (from a few GHz up to about 100 GHz) and the applied magnetic fields range from 0 up to a few T.
What is FMR linewidth?
Transition metal ferromagnetic films with perpendicular magnetic anisotropy (PMA) have ferromagnetic resonance (FMR) linewidths that are one order of magnitude larger than soft magnetic materials, such as pure iron (Fe) and permalloy (NiFe) thin films.
How is anisotropy constant calculated?
The formula to find anisotropic constant is Mα Tc = constant. Here, Mα is anisotropic constant and Tc is critical temperature. Tc is the temperature below which the substance becomes a superconductor.
What is meant by anisotropy?
anisotropy, in physics, the quality of exhibiting properties with different values when measured along axes in different directions. Anisotropy is most easily observed in single crystals of solid elements or compounds, in which atoms, ions, or molecules are arranged in regular lattices.
Why is timber anisotropic?
The wood is stronger with the grain than “against the grain”. Strength is a property of the wood and this property depends on the direction; thus it is anisotropic.
What is anisotropic effect with example?
What does high fluorescence anisotropy mean?
Fluorescence anisotropy or fluorescence polarization is the phenomenon where the light emitted by a fluorophore has unequal intensities along different axes of polarization.
What is the anisotropy of a magnetic field?
The anisotropy field H a represents the hypothetical field that would be able to align the magnetization perpendicular to the easy direction, the c -axis. It is defined by H a = 2 K 1 / J s 0, where the anisotropy constant K 1 characterizes the associated anisotropy energy.
What is the difference between GMR and anisotropic MRH?
Note, however, that fractional change in the resistance is the same. Thus, Δ R /2 (cos 30° – cos 150°) = 0.87Δ R for the GMR head, whereas Δ R (cos 2 15° – cos 2 75°) = 0.87Δ R in the anisotropic MRH case.
What is an anisotropy of microstructures?
Anisotropic microstructures can arise in amorphous alloys owing to their preparation. These microstructures may involve density or compositional fluctuations which produce internal shape effects, that is, variations in magnetization. The resultant anisotropy field can then be no greater than that for long rods, namely 2πMs.