Experience of MeV Electron Beam Application for In Situ Studies of Solids Yuri Petrusenko petrusenko@kipt.kharkov.ua NATIONAL SCIENCE CENTER Kharkov Institute of Physics & Technology “CYCLOTRON” Science & Research Establishment Kharkov, Ukraine
Co-operation: NATIONAL SCIENCE CENTER Kharkov Institute of Physics & Technology Ivan Neklyudov Alexander Bakai Oleksandr Astakhov Valeriy Borysenko Dmitro Barankov Vladimir Gann Igor Michailovskij Forschungszentrum Juelich, Germany Rainer Hoelzle Reinhard Carius Fridhelm Finger Hahn Meitner Institut Berlin, Germany Mikhael-Peter Macht,, Crystian Abromeit Nelly Wanderka
National Science Center “Kharkov Institute of Physics & Technology” Kharkov, Ukraine www.kip.kharkov.ua
National Science Center Kharkov Institute of Physics & Technology Found – in 1928 Staff – 2500 Institutes: • Institute of Solid State Physics Materials Science & Technologies • Institute of Nuclear Physics • Institute of Plasma Physics • Institute of Plasma Electronics & New Methods of Accelerating • Institute of Theoretical Physics Accelerators – more then 15
“CYCLOTON” Science & Research Establishment Status: Center of Joint Use of Accelerator Facilities Permanent staff: 17 (now) / up to 31 Basic facilities: • ELIAS electrostatic accelerator (High Voltage Corporation, USA) • Compact Cyclotron CV-28 (The Cyclotron Corporation of Berkeley, USA)
Parameters of “ELIAS” accelerator Parameters Values Energy of accelerated electrons 0.5- 3.0 MeV Beam current (without scanning) 0.5-150 µА Maximum beam current (with scanning) up to 500 µА 10 -4 radian Electron beam disperse Diameter of electron beam (without 1.0 сm focusing) Diameter of electron beam (with focusing), 0.1 cm for 90% capacity 1x10 -7 mbar Vacuum in the electron beam line Power consumption 20 кW
Irradiation with MeV electrons • Coulomb scattering of electrons by nuclei takes place, and recoil atoms appear: T max (E) = E * (E +E 0 ) * 2 / ( A * m p c 2 ) (E 0 = m e c 2 , m e – electron mass, m p – proton mass) • Damage cross-section: T ( E ) max d ( E , T ) σ ( E ) ( T ) dT ∫ σ = ν D dT E d • Damage production (dpa): D = σ D *Ф (Ф –electron fluence)
“ELIAS” electrostatic accelerator as precise generator of point defects in solids (E = 0.5 -3.0 MeV)
“ELIAS” Accelerator Critical current and vortex pinning in high-T c single crystals irradiated with MeV eltctrons • Whether point defect are effective pinning centers ? • A.V. Bondarenko, A.A. Prodan, Yu.T. Petrusenko et al. Phys. Rev. B (2001) 64, 092513. • Yu. T. Petrusenko and A. V. Bondarenko, Pinning and dynamics of vortices in YBaCuO crystal in magnetic field applied in vicinity of the ab-plane, to be published . • Yu. T. Petrusenko and A. V. Bondarenko, Interplay of point and planar defects in the formation of phase state and dynamics of vorties in YBa 2 Cu 3 O 7- δ crystals, to be published
• Experimental • Samples: High-quality YBaCuO single crystals, T c ≈ 93 K. • Irradiation: 2.5 MeV electrons a liquid helium cryostat at temperatures T ≤ 10 K at doses up to 3x10 18 el/cm 2 . • temperature range for operation from 10 to 400 K. • magnetic field up to 6T. • accuracy of temperature control and regulation 0.005 K. • a goniometric sample holder to rotate the crystals with respect to the vector of the magnetic field. • Technique: Current-voltage characteristics measured by dc-resistivity method.
YBa 2 Cu 3 O 7-X single crystal o , H =1.5 T T=77 K , angl H ,ab =14 18 el/cm 2 Fluence x10 0.5 2.0 0 3.1 1.2 0.4 E , mV/cm 0.3 0.2 0.1 0 10 20 30 40 50 60 70 80 2 Current density , kA/cm
35 30 86 K 25 J cirr / J co , arb. un. 83 K 20 15 79 K 10 77 K 5 0 18 18 18 0 1x10 2x10 3x10 Fluence , el / cm 2
• Conclusion It has been first demonstrated that point defects generated by the ~MeV electron beam are the effective pinning centers of magnetic vortices in high-Tc crystals, and this determines a substantial rise in the critical current density in irradiated superconductors.
“ELIAS” Accelerator • Point Defects and Recovery Kinetics in Irradiated Bulk Metallic Glasses • Yu. Petrusenko, A.Bakai, I. Neklyudov,et al., VANT , No 2 , (2008). • Yu. Petrusenko, A. Bakai et. al., Mater. Res. Soc. Symp. Proc. Vol. 104 8 (2008). Yu. Petrusenko, A. Bakai, et. al., Proc. 6 th Int. Conf.on Bulk Metallic Glasses (2008). • Yu. Petrusenko, Proc. 5 th Int. Conf. on Advanced Materials and Processing (2008) •
The problem of structural properties and structural defects of amorphous solids is still of vital importance. To make clear whether stable point defects exist in metallic glasses (MGs), we have studied the accumulation and recovery kinetics of radiation defects in ZrTiCuNiBe and ZrTiCuNiAl bulk MGs irradiated with 2.5 MeV electrons at T ~ 80 K.
• Experimental • The method: - low-temperature electron irradiation - isochronal annealing - electrical resistance measurements • Samples: amorphous alloys, Zr 41 Ti 14 Cu 12,5 Ni 10 Be 22,5 Zr 52.5 Ti 5 Cu 17.9 Ni 14.6 Al 10 , • 0.05 mm in thickness, prepared by the spinning method • • Irradiation: 2.5 MeV electrons at ELIAS electrostatic accelerator Maximal exposed dose 7.5x10 19 e - /cm 2 • Temperature of irradiation T irr ~80 K. • Isochronal annealing: temperature range 85-300 K, 10 K step • Electrical resistance measurements: at T= 80.5 K by precise fore-probe method, accuracy - 5 ppm
40 35 e > Zr 52.5 Ti 5 Cu 17.9 Ni 14.6 Al 10 30 25 ( i ) , barn ( Zr ) 20 s σ D , s 15 10 ( Ni ) s ( Cu ) 5 s ( Al ) s ( Ti ) s 0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 E, MeV Dependence of total and partial displacement damage cross- • sections on electron energy for Zr 52.5 Ti 5 Cu 17.9 Ni 14.6 Al 10
30 e --> Zr 46.8 Ti 8.2 Cu 7.5 Ni 10 Be 27.5 25 20 (i) , barn (Zr) s 15 σ D , s 10 5 (Be) (Ni) s s (Cu) s (Ti) s 0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 E, MeV Dependence of total and partial displacement damage cross- • sections on electron energy for Zr 46.8 Ti 8.2 Cu 7.5 Ni 10 Be 27.5
1,0016 1,0014 ZrTiCuNiBe 1,0012 1,0010 1,0008 1,0006 R irr /R 0 1,0004 1,0002 1,0000 0,9998 ZrTiCuNiAl 0,9996 0,9994 0,9992 0 20 40 60 80 18 e - /cm 2 D, x10 Dose dependences of relative electrical resistance for ZrTiCuNiBe and ZrTiCuNiAl irradiated with 2.5 MeV electrons at 85 K .
100 100-(R irr -R ann )/(R irr -R o ) , % 80 60 40 20 0 50 100 150 200 250 300 Tann , K Recovery of irradiation-induced resistance of ZrTiCuNiBe irradiated with 2.5 MeV electrons at 85 K to dose 7.5x10 19 e-/cm 2 .
-100 -110 -100-(R irr -R ann )/(R irr -R o ) -120 -130 -140 -150 -160 -170 -180 50 100 150 200 250 300 Tann , K Recovery of irradiation-induced resistance of ZrTiCuNiAl irradiated with 2.5 MeV electrons at 85K to dose 7.5x10 19 e-/cm 2
-6 5,0x10 -6 4,0x10 -6 3,0x10 dR / dT -6 2,0x10 -6 1,0x10 0,0 -6 -1,0x10 50 100 150 200 250 300 Tann , K Recovery spectrum of irradiation-induced resistance for ZrTiCuNiBe irradiated with 2.5 MeV electrons at 85 K to dose 7.5x10 19 e-/cm 2 .
-6 2,5x10 -6 2,0x10 -6 1,5x10 -6 1,0x10 dR /dT -7 5,0x10 0,0 -7 -5,0x10 -6 -1,0x10 50 100 150 200 250 300 Tann , K Recovery spectra of irradiation-induced resistance of ZrTiCuNiAl irradiated with 2.5 MeV electrons at 85K to dose 7.5x10 19 e-/cm 2
Effective activation energies of recovery stages for ZrTiCuNiAl and ZrTiCuNiBe bulk metallic glasses irradiated with 2.5 MeV electrons (Estimated data) • ZrTiCuNiBe: E 150K = 0.46 eV • E 225K = 0.69 eV • ZrTiCuNiAl : E 135K = 0.40 eV • E 225K = 0.69 eV
A fragment of the 2-D polycluster Intercluster and inner boundaries are shown. • -regular sites, circles with dot are coincident sites, semicircles with dot are noncoincident sites
Field ion microscopy image of the intercluster boundaries of the bulk metallic glass Zr 41 Ti 14 Cu 12,5 Ni 10 Be 22,5 A.S. Bakai et al. JETP Letters, 76 (2002) 218
Subclusters (a) (b) FIM images of bulk ZrTiCuNiBe alloy, obtained in result of field evaporation (а) and stimulating field etching in hidrogen (b)
The autoelectronic evaporation image of the Zr 41 Ti 14 Cu 12,5 Ni 10 Be 22,5 bulk metallic glass
1,4 1,2 1,0 2 ∆ Q/Q x10 0,8 0,6 0,4 0,2 0,0 0 5 10 15 20 25 L,í ì The evaporation field energy along the shown cross-section • It is seen that the width of the intercluster boundary is nearly 1nm, while the binding energy of atoms within the boundaries is on 0.13-0.43 eV less than in the cluster bulk
Sinks of point defects • Intercluster boundaries are the most probable sinks of the point defects. • The cluster sizes are varying from 5 to 10 nm. • The density of the point defects sinks is rather high, up to 10- 2 per atom.
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