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CR-39 imaged by atomic force microscope
Nut'/. Tmg~ ~_-~_~_ Mini., Vol. 22, Not I-4, pp. 249-2.q0, 1993 Fdtev~ Sgamee Lal Printed ia Gcmt lltitaia. 0969410711~t $6.00+.00
CR-39 IMAGED BY ATOMIC FORCE MICROSCOPE J. B. VUKOVlL"*and R. ANTANASDEVI~'I" *Instituteof Blophyucs,Facultyof Medganeand tInsfituteof Physics,Umvca'sltyof Belgrade,Belgrade,Yugoslavia
ABSTRACT The application of AFM (NanoScope II) for the surface imaging of allyldiglicol carbonate (CR-39) polymer shows great roughness from profile diagrams and direct visulisation of the surface which include polymer separate flakes. There is the idea for imaging free radicals ends by AFM or another type of SPM. KEYWORDS AF Microscope; CR-39 polymer; surface visualisation. INTRODUCTION The most impotrant success in microscopy is recent invention of Scanning tunneling microscope - STM (Binning and Roher, 1982. Nobel Prize 1986). Atomic force microscope (AFM noncontact) was the first microscope derived from STM (Binning et al., 1986). Also, a family of these new microscopes open this realm which is capable of resolving the surface detail down to atomic and molecular level (generally the Scanning probe microscopy SPM: STM, AFM, Frictional AFM - FAFM, Scanning ion conductance microscope-SICM (Harass et al. 1981) Scanning near field optical microscope - SNFOM, Photon STM - PSTM, Tunneling acoustic misroscope - TAM and others. The fundamental problems and their interpetation in the field of Nuclear tracks in solids - NTS (the tracks formation mechanism: direct production of atomic displacement, many brocken molecular chains in plastics - polymers i.e. generation of chemical free radicals and cross linking after, track structures before, during and after etching, silver halids microctystals and others) must be succefssully imaged by most of SPM. A number of papers recently published (Harass, 1989; Pengji, 1990, Kemmer, 1990; Antansijevi', 1990; Kemmer, 1991; Ackermann, 1991; Thibaudan, 1991). Pengji et al. reported the first observation of radiation damage of heavy ions on the surface of polycarbonate film using AFM. They present distorded region caused by Au ions impact. They estimated size of distorted region to about 600 nm and largest depth from the Z corrugation of the line scan 70 nm. Also, the nice STM image of the hole in policarbonate foil with depth profile after heavy ion irradiation (UNILAC - Kemmer, Grafstrom, 1991) and etching. The surface of the foil has great tunneling roughness. It is interesting to use SPM for revealing all structural modification by ionizing particle (at first latent tracks) recorded by electron microscope (TEM) in crystals, glass, evaporated thin films. Then, the observation of fission fragment tracks may start. Our idea of application AFM for visualisation tracks in polymeric solid at highest magnification lay to identified new chain ends after brockeen polymers chains. We believe that these places with higher chemical activity (starting points for faster etching) must be evident by ~ A t u ~/,-4-K
249
250
J.B. VUKOVI~ and R. ANTANASDEVI(~
A F M or by any of the other type of SPM.
MATERIAL AND METHOD Imaging by AFM demand that the sample is immobile and that it can withstand the forces being applied by tip of the AFM during scanning. These forces are about 1 nN. The AFM used in this study detects vertical motion of the tip by sennsing the deflection of the reflected laser beam at two segment photodiode. The sample for scanning moved latteraly under the tip and feedback loop kept vertical position of the tip constant by moving the surface up and down with piezoelectric translator (NanoScope II, Digital Inst., Inc.). The CR-39 (Allyldiglicolecarbonate) plate (dim: I × I x 0.1crn 3 ) Was irradiated by aplha particles and etched. The speciment need not any more treatment for A F M imaging. RESULTS AND CONCLUSIONS The first impression of the images at different scales ("magnification": 15pro = 2cm, 5pro -2cm and 1.5pro = 2cm) are that the surface has some type of granular structure. According to Fig. 1 these granules present CR-39 polymer flakes of different size (white islandd) and empty place between flakes (black bottom). Profile analysis speak about great roughness of the surface and also a three dimension image mode present many hills from polymer flaks (insert on Fig.l). The Fig.2 at very high scale achieves some evidence on the macromolecular level looks is very faintly (white area). Probably only individal macromolecules from solution are real specimen for analysing the chain break by ionizing radiation.
4:
Fig.1. CR-39 AFM image (square 80 n m Z=100 nm). Insert 3D mode.
2
Fig.2. CR-39 AFM image (square 65 rzm~ , Z=3 nm).
REFERENCES
Ackerman J., et al. (1991) GSI Sci. Rep. p.253 Antanasijevi' R., et al. (1991) Nucl. Tracks. Rad. Meas. 19, Nos I-4, 555. Binning G., H. Roher et. al. (1982) Phys. Rev. Lett. 49(1), 57-61. Binning G., et al. (1986) Phys. Rev. Lett. 56, 930 Hamsa P.K., et al. (1959) Science, 243, 641. Kemmer H., et al. (1990) GSI Sci. Rep. p. 249 Kemmer H., et al. (1991) GSI Sci. Rep. p. 253 Penni Z. et al. (1990) GSI Sci. Rep. p.248 Tibaudau F., et al. (1991) Phys. Rev. Lett. 67, 1528.
CR-39 IMAGED BY ATOMIC FORCE MICROSCOPE J. B. VUKOVlL"*and R. ANTANASDEVI~'I" *Instituteof Blophyucs,Facultyof Medganeand tInsfituteof Physics,Umvca'sltyof Belgrade,Belgrade,Yugoslavia
ABSTRACT The application of AFM (NanoScope II) for the surface imaging of allyldiglicol carbonate (CR-39) polymer shows great roughness from profile diagrams and direct visulisation of the surface which include polymer separate flakes. There is the idea for imaging free radicals ends by AFM or another type of SPM. KEYWORDS AF Microscope; CR-39 polymer; surface visualisation. INTRODUCTION The most impotrant success in microscopy is recent invention of Scanning tunneling microscope - STM (Binning and Roher, 1982. Nobel Prize 1986). Atomic force microscope (AFM noncontact) was the first microscope derived from STM (Binning et al., 1986). Also, a family of these new microscopes open this realm which is capable of resolving the surface detail down to atomic and molecular level (generally the Scanning probe microscopy SPM: STM, AFM, Frictional AFM - FAFM, Scanning ion conductance microscope-SICM (Harass et al. 1981) Scanning near field optical microscope - SNFOM, Photon STM - PSTM, Tunneling acoustic misroscope - TAM and others. The fundamental problems and their interpetation in the field of Nuclear tracks in solids - NTS (the tracks formation mechanism: direct production of atomic displacement, many brocken molecular chains in plastics - polymers i.e. generation of chemical free radicals and cross linking after, track structures before, during and after etching, silver halids microctystals and others) must be succefssully imaged by most of SPM. A number of papers recently published (Harass, 1989; Pengji, 1990, Kemmer, 1990; Antansijevi', 1990; Kemmer, 1991; Ackermann, 1991; Thibaudan, 1991). Pengji et al. reported the first observation of radiation damage of heavy ions on the surface of polycarbonate film using AFM. They present distorded region caused by Au ions impact. They estimated size of distorted region to about 600 nm and largest depth from the Z corrugation of the line scan 70 nm. Also, the nice STM image of the hole in policarbonate foil with depth profile after heavy ion irradiation (UNILAC - Kemmer, Grafstrom, 1991) and etching. The surface of the foil has great tunneling roughness. It is interesting to use SPM for revealing all structural modification by ionizing particle (at first latent tracks) recorded by electron microscope (TEM) in crystals, glass, evaporated thin films. Then, the observation of fission fragment tracks may start. Our idea of application AFM for visualisation tracks in polymeric solid at highest magnification lay to identified new chain ends after brockeen polymers chains. We believe that these places with higher chemical activity (starting points for faster etching) must be evident by ~ A t u ~/,-4-K
249
250
J.B. VUKOVI~ and R. ANTANASDEVI(~
A F M or by any of the other type of SPM.
MATERIAL AND METHOD Imaging by AFM demand that the sample is immobile and that it can withstand the forces being applied by tip of the AFM during scanning. These forces are about 1 nN. The AFM used in this study detects vertical motion of the tip by sennsing the deflection of the reflected laser beam at two segment photodiode. The sample for scanning moved latteraly under the tip and feedback loop kept vertical position of the tip constant by moving the surface up and down with piezoelectric translator (NanoScope II, Digital Inst., Inc.). The CR-39 (Allyldiglicolecarbonate) plate (dim: I × I x 0.1crn 3 ) Was irradiated by aplha particles and etched. The speciment need not any more treatment for A F M imaging. RESULTS AND CONCLUSIONS The first impression of the images at different scales ("magnification": 15pro = 2cm, 5pro -2cm and 1.5pro = 2cm) are that the surface has some type of granular structure. According to Fig. 1 these granules present CR-39 polymer flakes of different size (white islandd) and empty place between flakes (black bottom). Profile analysis speak about great roughness of the surface and also a three dimension image mode present many hills from polymer flaks (insert on Fig.l). The Fig.2 at very high scale achieves some evidence on the macromolecular level looks is very faintly (white area). Probably only individal macromolecules from solution are real specimen for analysing the chain break by ionizing radiation.
4:
Fig.1. CR-39 AFM image (square 80 n m Z=100 nm). Insert 3D mode.
2
Fig.2. CR-39 AFM image (square 65 rzm~ , Z=3 nm).
REFERENCES
Ackerman J., et al. (1991) GSI Sci. Rep. p.253 Antanasijevi' R., et al. (1991) Nucl. Tracks. Rad. Meas. 19, Nos I-4, 555. Binning G., H. Roher et. al. (1982) Phys. Rev. Lett. 49(1), 57-61. Binning G., et al. (1986) Phys. Rev. Lett. 56, 930 Hamsa P.K., et al. (1959) Science, 243, 641. Kemmer H., et al. (1990) GSI Sci. Rep. p. 249 Kemmer H., et al. (1991) GSI Sci. Rep. p. 253 Penni Z. et al. (1990) GSI Sci. Rep. p.248 Tibaudau F., et al. (1991) Phys. Rev. Lett. 67, 1528.