Self-organized nanostructure formation on the graphite surface induced by helium ion irradiation

2018 ◽  
Vol 382 (24) ◽  
pp. 1601-1608 ◽  
Author(s):  
N.J. Dutta ◽  
S.R. Mohanty ◽  
N. Buzarbaruah ◽  
M. Ranjan ◽  
R.S. Rawat
Keyword(s):  
Ion Irradiation ◽  
Graphite Surface ◽  
Nanostructure Formation ◽  
Self Organized ◽  
Helium Ion

Magnetization dynamics of irradiation-fabricated perpendicularly magnetized dots inside a softer magnetic matrix

2003 ◽  
Vol 777 ◽  
Author(s):  
T. Devolder ◽  
M. Belmeguenai ◽  
C. Chappert ◽  
H. Bernas ◽  
Y. Suzuki
Keyword(s):  
Domain Wall ◽  
Magnetic Anisotropy ◽  
Magnetization Reversal ◽  
Ion Irradiation ◽  
Magnetic Nanostructures ◽  
Magnetic Storage ◽  
Exchange Field ◽  
Static Magnetization ◽  
Specific Domain ◽  
Helium Ion

AbstractGlobal Helium ion irradiation can tune the magnetic properties of thin films, notably their magneto-crystalline anisotropy. Helium ion irradiation through nanofabricated masks can been used to produce sub-micron planar magnetic nanostructures of various types. Among these, perpendicularly magnetized dots in a matrix of weaker magnetic anisotropy are of special interest because their quasi-static magnetization reversal is nucleation-free and proceeds by a very specific domain wall injection from the magnetically “soft” matrix, which acts as a domain wall reservoir for the “hard” dot. This guarantees a remarkably weak coercivity dispersion. This new type of irradiation-fabricated magnetic device can also be designed to achieve high magnetic switching speeds, typically below 100 ps at a moderate applied field cost. The speed is obtained through the use of a very high effective magnetic field, and high resulting precession frequencies. During magnetization reversal, the effective field incorporates a significant exchange field, storing energy in the form of a domain wall surrounding a high magnetic anisotropy nanostructure's region of interest. The exchange field accelerates the reversal and lowers the cost in reversal field. Promising applications to magnetic storage are anticipated.

The role of asymmetric excitation in self-organized nanostructure formation upon femtosecond laser ablation

2011 ◽  
Vol 104 (3) ◽  
pp. 969-973 ◽  
Author(s):  
Juergen Reif ◽  
Olga Varlamova ◽  
Sergej Varlamov ◽  
Michael Bestehorn
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Nanostructure Formation ◽  
Self Organized

The influence of helium ion irradiation on amorphous hydrocarbon films

2013 ◽  
Vol 435 (1-3) ◽  
pp. 214-221 ◽  
Author(s):  
Hongyu Fan ◽  
Li Sun ◽  
Deming Yang ◽  
Jinhai Niu ◽  
Liping Guo ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Hydrocarbon Films ◽  
Helium Ion

Spontaneous formation of nanometer-scale self-organized structures in Ag-Cu alloys under irradiation

2000 ◽  
Vol 647 ◽  
Author(s):  
Raúl A. Enrique ◽  
Pascal Bellon
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Solute Concentration ◽  
Irradiation Temperature ◽  
Nanometer Scale ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
Ion Beam Irradiation ◽  
Self Organized ◽  
The One

AbstractIon-beam irradiation can be used as a processing tool to synthesize metastable materials. A particular case is the preparation of solid solutions from immiscible alloys, which have been achieved for a whole range of systems. In this process, enhanced solute concentration is obtained through the local mixing induced by each irradiation event, which if occurring at a high enough frequency, can outweigh demixing by thermal diffusion. The resulting microstructure forms in far from equilibrium conditions, and theoretical results for these kind of driven alloys have shown that novel microstructures exhibiting self-organization can develop. To test these predictions, we prepare Ag-Cu multilayered thin films that we subject to 1 MeV Kr+-ion irradiation at temperatures ranging from room temperature to 225 °C, and characterize the specimens by x-ray diffraction, TEM and STEM. We observe two different phenomena occurring at different length scales: On the one hand, regardless of the irradiation temperature, grains grow under irradiation until reaching a size limited by film thickness (~200 nm). On the other hand, the distribution of species inside the grains is greatly affected by the irradiation temperature. At intermediate temperatures, a semi-coherent decomposition is observed at a nanometer scale. This nanometer-scale decomposition phenomenon appears as an evidence of patterning, and thus confirms on the possibility of using ion-beam irradiation as a route to synthesize nanostructured materials with novel magnetic and optical properties.

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