| 1. |
- Lukashevich, M.G., et al.
(författare)
-
Magnetoresistive effect in PET films with iron nanoparticles synthesised by ion implantation
- 2010
-
Ingår i: The Open Applied Physics Journal. - 1874-1835. ; 3, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- Thin polyethyleneterephthalate (PET) layers with Fe nanoparticles (NPs) were synthesised by high-fluence ion implantation. Temperature dependence of conductance and magnetoresitance were studied as a function of ion fluence. It is found that the implantation with fluences of about 1.0×1017 cm-2 causes high enough concentration of metal inclusions to provide conditions for electrical percolation that leads to an insulator-to-metal transition (IMT) in charge carrier transport mechanisms. The magnetoresistance measurements indicate that the magnetic percolation takes place at metal concentrations (fluences) lower than those needed for the electrical percolation. For the samples on insulating side of the IMT, a non-monotonous dependence of resistance in an increasing external magnetic field is observed due to anisotropic magnetoresistive effect and charge carrier scattering on magnetic inclusions. For the samples implanted with fluences > 1.0×1017 cm-2, the magnetoresistance becomes a monotonous decreasing function of the external magnetic field which is typical for ferromagnetic metals that indicates effective magnetic coupling of the iron inclusions.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Popok, Vladimir, 1966, et al.
(författare)
-
Charge carrier transport in polyimide with Co nanoparticles formed by ion implantation
- 2004
-
Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 566-568:1-3 PART 1, s. 327-331
-
Tidskriftsartikel (refereegranskat)abstract
- Temperature dependence of resistance is studied for polyimide (PI) samples implanted by Co+ ions with fluences of 2.5x1016-1.25x1017 cm-2 at ion current densities of 4, 8 and 12 uA.cm-2. It is found that electron transport in the implanted samples originates from radiation-induced changes of the PI and Co nanoparticle formation and it depends dramatically on the ion current density. A variable range hopping mechanism dominates for all fluences at a low ion current density of 4 uA.cm-2 while a transition to a semimetallic type of conductance is observed with an increase in ion current density due to agglomeration of the Co nanoparticles forming a percolation way for the charge carriers. It is shown that both quantum effects of weak localisation and electron-electron interaction give a significant contribution to the transport mechanism.
|
|
| 9. |
- Abudurexiti, A, et al.
(författare)
-
Taxonomy of the order Bunyavirales: update 2019
- 2019
-
Ingår i: Archives of virology. - : Springer Science and Business Media LLC. - 1432-8798 .- 0304-8608. ; 164:7, s. 1949-1965
-
Tidskriftsartikel (refereegranskat)
|
|
| 10. |
- Lukashevich, M.G., et al.
(författare)
-
Modification of magnetic properties of polyethyleneterephthalate by iron ion implantation
- 2007
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. ; 257:1-2, s. 589-592
-
Tidskriftsartikel (refereegranskat)abstract
- Fe+ ions (40 keV) were implanted into polyethyleneterephthalate (PET) films with fluences of (0.25–1.5) × 1017 cm−2. Magnetic properties of the synthesised Fe:PET composites were studied using superconducting quantum interference device (SQUID) technique in temperature range of 2–300 K. For range of fluences (0.5–0.75) × 1017 cm−2 the samples reveal superparamagnetic behaviour at room temperature. At fluences above 0.75 × 1017 cm−2 the strong increase of magnetisation and transition to ferromagnetic properties are registered. Analysis of the magnetic hysteresis loops suggests an easy plane magnetic anisotropy similar to that found for thin magnetic films. Zero-field-cooled (ZFC) and field-cooled (FC) temperature measurements of magnetisation are found to be in agreement with earlier observed formation of Fe nanoparticles (NPs) in the implanted layers. The growth and agglomeration of the NPs forming the quasi-continuous labyrinth-like structure in the polymer film at the highest implantation fluence of 1.5 × 1017 cm−2 is an origin for the transition to the ferromagnetic properties.
|
|
