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RESEARCH PRODUCT
Polymerization and Damage of C60 Single Crystals under Low Fluency Laser Irradiation
I. ManikaDonats ErtsJanis ManiksR. PokulisJ. Kalnacssubject
Materials scienceCondensed Matter PhysicsLaserIndentation hardnessElectronic Optical and Magnetic Materialslaw.inventionCrystallographyPolymerizationlawHardening (metallurgy)SubstructureIrradiationComposite materialDislocationPower densitydescription
Photo-induced hardening, substructure formation and damage of C 60 single crystals under the 632.8 nm He-Ne laser irradiation in air at a power density of 1.47 mW/mm 2 was investigated by microhardness and AFM methods. Photo-induced formation of the dislocation substructure and crystallographically oriented crack patterns on the (111) face due to lattice contraction on polymerization were observed. Two phototransformed states: soft (400-450 MPa) and hard (650-1000 MPa) are found to appear under laser-irradiation. Hard fullerite is created in the subsurface layer < 1 μm at the saturation stage of phototransformation. It softens to 400-450 MPa at 340 K and reverts to non-polymerized state at 470-480 K. The effect of post-irradiation hardening, which appears as an increase of the hardness of laser-irradiated crystals after storage in air in the dark, has been discovered.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-12-01 | physica status solidi (a) |