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3.2 Radiation of coherent spin waves by rectangular magnetic heterogeneity at action v/ch a rating homogeneous field

In section 3.1 it has been shown, that magnetic interfaces can generate coherent spin waves with length much more shortly the gauges of length related to the MICROWAVE MAGNETIC FIELD of a rating. The theory has shown a special role of distinction in dynamic magnetic properties of two magnonnyh the mediums parted by the interface in this process.

In it difference from usual interpretation shlemanovskogo the mechanism of excitation of a spin wave that underlines a coordination role between impinging microwave frequency and local frequency FMR consists. Last interpretation is represented especially doubtful in case of generation CB at reduction, instead of magnification of local frequency FMR as it is specified in [45,96] where frequency of an impinging MICROWAVE FIELD mismatched a local resonant frequency in any point of the sample. We explore interrelation between two interpretations, having chosen as model rectangular magnetic heterogeneity which can be viewed or as change of local frequency FMR or as system from two interfaces. Besides, given analysis shows a close connection between efficiency of radiation of spin wave SHlyomana and properties of dispersion of a spin wave in the presence of magnetic heterogeneity. It is possible to expect, that at generation CB of each of two boundaries of a stratum they are capable to interfere among themselves so, that under certain conditions it is possible to expect their cross amplification.

Let's consider, that a stratum of magnetic medium A {-dlr2 1, emitted on medium In, we will present in a view:

In drawing 3.3 dependence Cb 1от is shown to. Predictably, this dependence is characterised by prompt decrease Cb 1при major to. At ω0 b ω0 And, shows the periodic beats which continuance decreases with magnification of a thickness of a stratum of A.Eto is related to change of a phase of the net undular field in a stratum And on demarcations as it was discussed earlier. On the contrary, on the inferior panel in the drawing 3.4, corresponding ω0 in к0 And = 0.6 are visible. At smaller values to, both CB from a stratum Instead of are spread, and exponentially damp. It is necessary to remember, that SV, radiated in opposite directions from the isolated interface, have opposite phases and an exponential damping (tunneling) does not lead to phase change. Using it it is possible to expect, that the emitted
Two interfaces of a wave in one direction in medium In interfere destructively. It can be seen on the inferior panel of drawing 3.4 as sharp dip Cb∕Cb 1ПРИ values to hardly smaller к for δ = 10, and as inhibition of radiation CB at small to for small thickness of stratum A (δ = 0.5 or 1). For δ = 10 it is possible to see that, at to much smaller Zc0 And, this decrease very prompt so relation Cb∕Cb 1порядка unities, i.e. - amplitudes SV, emitted by the isolated interface and a stratum are practically identical.

Drawing 3.4. Dependence of the relation of amplitudes Cb∕Cb 1эмитируемой CB from to for a stratum (Cb) and isolated interface A/V (Cb i) is shown for values δ = 0.5,1, 3,10 - the dimensionless thickness of a stratum of A.Verhnjaja and inferior panel correspond Zcao = 0.1 and Zcao = 0.6. For both cases ∕⅛ 0 = 0.2, aa = tzB = 0.01

In drawing 3.5 influence of a constant of signal attenuation in a stratum is explored And on efficiency of issue ST. it is obvious, the effect is small enough - only inappreciable inhibition of peaks and zero of amplitudes of radiation is observed at great values to. At even great values to the relation (is not shown)
Cb∕Cbiмедленно Comes nearer to unity, i.e. the stratum And behaves more and more as the isolated interface.

Drawing 3.5. Dependence from to the relation of amplitudes emitted CB Cb∕Cb 1 for stratum A (Cb) and isolated interface AZB (Cb i) is shown for 1. ka 0 = 0.1, aa = 0.01; 2. кА0 = 0.1, aa = 0.05; 3. кА0 = 0.6, aa = 0.01; 4. кА0 = 0.6, aa = 0.05. In all cases, δ = 10, kv 0 = 0.2,

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A source: Pojmanov Vladislav Dmitrievich. DISTRIBUTION, DISPERSION And GENERATION of SPIN WAVES To the NONUNIFORM MAGNETIC STRUCTURES. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Donetsk - 2018. 2018

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