scholarly journals High-energy ion beam irradiation of Co/NiFe/Co/Cu multilayers: Effects on the structural, transport and magnetic properties

2008 ◽  
Vol 516 (8) ◽  
pp. 2087-2093 ◽  
Author(s):  
P.L. Grande ◽  
L.C.C.M. Nagamine ◽  
J. Morais ◽  
M.C.M. Alves ◽  
G. Schiwietz ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ion Beam ◽  
High Energy ◽  
Beam Irradiation ◽  
Ion Beam Irradiation

Modification of the magnetic properties of longitudinal thin-film media by ion-beam irradiation

2001 ◽  
Vol 674 ◽  
Author(s):  
Jason D. Wright ◽  
Kannan M. Krishnan
Keyword(s):  
Thin Film ◽  
Magnetic Properties ◽  
Ion Implantation ◽  
Ion Beam ◽  
High Coercivity ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Patterned Media ◽  
Chromium Ion ◽  
Stencil Mask

ABSTRACTThe modification of conventional longitudinal recording media by ion-beam irradiation is of both scientific and technological interest. In particular, patterning by irradiation through a stencil mask at the 50 nm length scale may fulfill the promise of a commercially viable patterned media architecture. In this context, the magnetic properties and microstructural evolution of high-coercivity longitudinal thin film media were investigated after ion-beam irradiation. TRIM simulations were used to calculate the depth profiles and damage distributions as a function of energy and dose for carbon, nitrogen, and chromium ions and three different media (C, Cr, no capping layer). Corresponding implantations were carried out and hysteresis curves were measured using a vibrating sample magnetometer (VSM). Using chromium ion implantation at 20 keV, both remanence and coercivity were reduced to zero, i.e., rendering the ferromagnetic thin film paramagnetic, at doses as low as 1×1016 cm−2. For C+ implantation at 20 keV, remanence and coercivity were also reduced to varying extent up to doses of 5×1016 cm−2 after which further irradiation had no effect. Slight decreases in remanence and coercivity were observed for 20 keV N2+ irradiation. XRD measurements indicate that the hexagonal cobalt alloy phase remains intact after irradiation. The physical and magnetic domain structures at the surface were assessed by atomic force and magnetic force microscopy. Combined with the development of a suitable stencil mask, such chromium ion implantation can be used to develop a viable patterned media with nanoscale dimensions, consisting of locally defined ferromagnetic and paramagnetic regions. This work is in progress.

Modification and Study of Polymer Films Using High Energy Ion Beams

1983 ◽  
Vol 25 ◽  
Author(s):  
T. Venkatesan
Keyword(s):  
Polymer Films ◽  
Ion Beam ◽  
Composite Films ◽  
High Energy ◽  
Carbon Films ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Inorganic Composites ◽  
Yield Information ◽  
High Energy Ions

ABSTRACTRecent results on the effects of high energy ion beam irradiation in polymer films are reviewed in this paper. High energy ions (>10 keV/amu) deposit a large amount of energy (∼several cV/atom) in ionizing the electrons of the target atoms. This results in significant destruction of bonds in the films as a result of which polymers undergo rapid dissociation. Using a quadrupole mass spectrometer the study of transient emission of molecular species produced by an ion pulse has been shown to yield information about the diffusion and reaction kinetics of various molecules in the polymer. The fact that polymers undergo dissociation and those atoms which form volatile species are selectively depleted from the film could be utilized in producing useful inorganic composites by ion bombardment of polymers. For example, hard SiC composite films have been produced by ion beam irradiation of organo-silicon polymers. Eventually, polymer dissociation leads to a predominately carbon containing film which exhibits interesting electronic transport properties. Experiments on ion irradiated, pure carbon films indicate that a metallic form of carbon is produced from the polymer films at high irradiation doses.

Modification of magnetic anisotropy in metallic glasses using high-energy ion beam irradiation

Pramana ◽  
2002 ◽  
Vol 58 (5-6) ◽  
pp. 1093-1100 ◽  
Author(s):  
KV Amrute ◽  
UR Mhatre ◽  
SK Sinha ◽  
DC Kothari ◽  
R Nagarajan ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Metallic Glasses ◽  
Ion Beam ◽  
High Energy ◽  
Beam Irradiation ◽  
Ion Beam Irradiation

Comparison of Conductivity Produced in Polymers and Carbon Films by Pyrolysis and High Energy Ion Irradiation

1983 ◽  
Vol 27 ◽  
Author(s):  
T. Venkatesan ◽  
R. C. Dynes ◽  
B. Wilkens ◽  
A. E. White ◽  
J. M. Gibson ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Carbon Film ◽  
Physical Nature ◽  
High Energy ◽  
Carbon Films ◽  
Chemical Degradation ◽  
Beam Irradiation ◽  
Ion Beam Irradiation

ABSTRACTThe electrical properties of pyrolyzed polymers have been studied recently.1,2 It has been shown that organic, polymeric3 and non-polymeric4 films can be made conductive (ρ ~ 10−3Ωcm) by ion beam irradiation. Common to all of the films was the presence of carbon as a constituent element and both pyrolysis and ion beam irradiation3 was shown to increase the relative carbon content of the films. The ion beam irradiated organic films 3,4 exhibited a temperature dependence of their resistivity of the form ρ(T) = ρ∞e−(TЛ)*, where ρ is the ion-induced resistivity, ρ∞ and T0 are constants and T is the temperature. At very high doses of irradiation (1017cm−2Ar+@ 2MeV) the film resistivity was temperature independent. Very similar transport properties were observed in the pyrolyzed polymers1 as well, though the lowest resistivities achieved were higher than the resistivity values observed in the ion irradiated3 polymer films. In both the pyrolysis and ion-irradiation experiments the temperature dependence has been explained by a model due to Sheng and Abeles,5 which involves charge transport by hopping between conducting islands embedded in an insulating matrix. Such striking similarities between two distinctly different modes of energy deposition in the films, prompted us to compare the effects of pyrolysis and ion irradiation in different carbon containing films. We compared both a polymer (HPR-204°) and a film of electron beam evaporated carbon film. While in the former case one would observe chemical degradation as well as structural modification, by studying pure carbon films the physical nature of the processes could be clarified. We report metallic carrier densities in both films and evidence for significant structural rearrangement. We conclude that pyrolysis and ion beam irradiation have similar effects on both polymer and carbon films.

scholarly journals Improvement of gas sensitivity for a polymer membrane electrode by high-energy ion beam irradiation

2011 ◽  
Vol 36 (3) ◽  
pp. 321-324
Author(s):  
T. Tanaka ◽  
A. Yamada ◽  
Y. Suzuki ◽  
T. Kobayashi ◽  
K. Takahashi ◽  
...  
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Polymer Membrane ◽  
Membrane Electrode ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Gas Sensitivity

Defects engineering and enhancement in optical and structural properties of 2D-MoS2 thin films by high energy ion beam irradiation

2021 ◽  
pp. 125422
Author(s):  
Deepika Gupta ◽  
Vishnu Chauhan ◽  
Sonica Upadhyay ◽  
N. Koratkar ◽  
Fouran Singh ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Ion Beam ◽  
High Energy ◽  
Beam Irradiation ◽  
Ion Beam Irradiation

Radiation-Induced Nanostructures in an Iron Phosphate Glass

2003 ◽  
Vol 792 ◽  
Author(s):  
K. Sun ◽  
T. Ding ◽  
L.M. Wang ◽  
R.C. Ewing
Keyword(s):  
Phosphate Glass ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Dose Range ◽  
Iron Phosphate ◽  
High Energy ◽  
High Dose ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Feo Nanoparticles

ABSTRACTElectron and ion irradiation-induced nanostructures in an iron phosphate glass with a composition of 45 mol%Fe2O3-55 mol%P2O5 have been characterized by advanced electron microbeam techniques. Analysis by energy-filtered transmission electron microscopy indicated that Fe-rich and P-rich nanophases were formed when the glass was irradiated under a broad (with a diameter of 1.2μm) electron beam [give the dose range]. Phase separation developed with the increase in electron dose (from 1.0×1026e/m2 to 4.8×1026e/m2) as a result of the formation of an Fe-rich phase and pure P-phase. The formation of the Fe-rich and the P-phases are thought to be due to mainly ionization process. Under a low energy ion beam irradiation, Fe/FeO nanoparticles were formed, as confirmed by selected-area electron diffraction analysis. However, no nanoparticles were observed under a high-energy high-dose ion irradiation. The ion beam-irradiation results suggest that the formation of the Fe/FeO nanoparticles was due to preferential sputtering during ion irradiation and that the nanoparticles lie within the surface layers of the glass.

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