Resonant Precession of Magnetization and Precession - Induced DC voltages in FeGaB Thin Films

Abstract Measurements of frequency dependent ferromagnetic resonance (FMR) and spin pumping driven dc voltage (Vdc) are reported for amorphous films of Fe78Ga13B9 (FeGaB) alloy to address the phenomenon of self-induced inverse spin Hall effect (ISHE) in plain films of metallic ferromagnets. The Vdc signal, which is antisymmetric on field reversal, comprises of symmetric and asymmetric Lorentzians centered around the resonance field. Dominant role of thin film size effects is seen in setting the magnitude of static magnetization, Vdc and dynamics of magnetization precession in thinner films (≤ 8 nm). The film thickness dependence of magnetization parameters indicates the presence of a magnetically disordered region at the film – substrate interface, which may promote preferential flow of spins generated by the precessing magnetization towards the substrate. However, the Vdc signal also draws contributions from rectification effects of a ≈ 0.4 % anisotropic magnetoresistance and a large (≈ 54 nΩ.m) anomalous Hall resistivity (AHR) of these films which ride over the effect of spin – orbit coupling driven spin-to-charge conversion near the film – substrate interface. We have addressed these data in the framework of the existing theories of electrodynamics of a ferromagnetic film subjected to radio-frequency field in a coplanar waveguide geometry. Our estimation of the self-induced ISHE for the sample with 54 nΩ.m AHR shows that it may contribute significantly (≈ 90%) to the measured symmetric voltage. This study is expected to be very useful for fully understanding the spin pumping induced dc voltages in metallic ferromagnets with disordered interfaces and large anomalous Hall effect.

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Parallel Glide: A Fundamentally Different Type of Dislocation Motion in Ultrathin Metal Films

MRS Proceedings ◽

10.1557/proc-779-w4.4 ◽

2003 ◽

Vol 779 ◽

Author(s):

T. John Balk ◽

Gerhard Dehm ◽

Eduard Arzt

Keyword(s):

Thermal Cycling ◽

Grain Boundaries ◽

Film Surface ◽

Metal Films ◽

Geometric Constraints ◽

Film Stress ◽

Diffusional Creep ◽

Creep Model ◽

Substrate Interface ◽

Film Substrate

AbstractWhen confronted by severe geometric constraints, dislocations may respond in unforeseen ways. One example of such unexpected behavior is parallel glide in unpassivated, ultrathin (200 nm and thinner) metal films. This involves the glide of dislocations parallel to and very near the film/substrate interface, following their emission from grain boundaries. In situ transmission electron microscopy reveals that this mechanism dominates the thermomechanical behavior of ultrathin, unpassivated copper films. However, according to Schmid's law, the biaxial film stress that evolves during thermal cycling does not generate a resolved shear stress parallel to the film/substrate interface and therefore should not drive such motion. Instead, it is proposed that the observed dislocations are generated as a result of atomic diffusion into the grain boundaries. This provides experimental support for the constrained diffusional creep model of Gao et al.[1], in which they described the diffusional exchange of atoms between the unpassivated film surface and grain boundaries at high temperatures, a process that can locally relax the film stress near those boundaries. In the grains where it is observed, parallel glide can account for the plastic strain generated within a film during thermal cycling. One feature of this mechanism at the nanoscale is that, as grain size decreases, eventually a single dislocation suffices to mediate plasticity in an entire grain during thermal cycling. Parallel glide is a new example of the interactions between dislocations and the surface/interface, which are likely to increase in importance during the persistent miniaturization of thin film geometries.

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Transmission Electron Microscopy of the CVD Diamond Film/Substrate Interface.

10.21236/ada234790 ◽

1991 ◽

Author(s):

Dan Shechtman

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Diamond Film ◽

Cvd Diamond ◽

Substrate Interface ◽

Transmission Electron ◽

Cvd Diamond Film ◽

Film Substrate

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Photo-crystallization in a-Se layer structures: Effects of film-substrate interface-rigidity

Journal of Applied Physics ◽

10.1063/1.4902166 ◽

2014 ◽

Vol 116 (19) ◽

pp. 193511 ◽

Cited By ~ 5

Author(s):

G. P. Lindberg ◽

T. O'Loughlin ◽

N. Gross ◽

A. Mishchenko ◽

A. Reznik ◽

...

Keyword(s):

Substrate Interface ◽

Layer Structures ◽

Film Substrate

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Self-Ordered Vicinal-Surface-Like Nanosteps at the Thin Metal-Film/Substrate Interface

The Journal of Physical Chemistry C ◽

10.1021/jp303205n ◽

2012 ◽

Vol 116 (22) ◽

pp. 12149-12155 ◽

Cited By ~ 2

Author(s):

Shirly Borukhin ◽

Cecile Saguy ◽

Maria Koifman ◽

Boaz Pokroy

Keyword(s):

Metal Film ◽

Thin Metal Film ◽

Thin Metal ◽

Vicinal Surface ◽

Substrate Interface ◽

Film Substrate

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Nucleation and Heterointerface Structure of InAs Epilayers Grown on InP Substrates

MRS Proceedings ◽

10.1557/proc-280-453 ◽

1992 ◽

Vol 280 ◽

Author(s):

K. S. Chandra Sekhar ◽

A. K. Ballal ◽

L. Salamanca-Riba ◽

D. L. Partin

Keyword(s):

Surface Morphology ◽

Electronic Properties ◽

Growth Temperature ◽

High Speed ◽

Interface Roughness ◽

Structural Defects ◽

Lower Growth ◽

Substrate Interface ◽

Film Substrate ◽

Inp Substrates

ABSTRACTHeteroepitaxial growth of indium arsenide films on indium phosphide substrates is being actively pursued since the electronic properties of these films make them promising materials for optoelectronic and other high speed devices. The various structural aspects of the film that affect their electronic properties are structural defects like dislocations, film-substrate interface roughness and chemical inhomogeneities. In InAs films, electrons accumulate at the film-air interface, making surface morphology an important factor that decides the electronic properties. The InAs films used in this study were grown on InP substrates by metal organic vapor deposition, at different temperatures. A higher growth temperature not only resulted in poor surface morphology of the film, but also created a rough film-substrate interface. However, at all deposition temperatures, the film-substrate interfaces are sharp. At lower growth temperature, the interfaces were flat. Films grown at lower temperatures had good surface morphology and a flat and shaip heterointerface.

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