1. Visualization Abrikosov’s Vortices by Decoration Method in Novel Superconductors
L.Ya. Vinnikov
L.A, Emelchenko ISSP RAS, Chernogolovka, RUSSIA
F.L. Barkov
J.Karpinskii ETH-Zurich, SWITZERLAND
S.M.Kazakov
J. Jun
J.Anderegg AMESLAB,ISU, AMES, USA
S.L.Budko
P.C.Canfield
V.Kogan

2. History(outline)
Add pictures –vortex pinning for YBCO123 by twin boundaries

3. Anisotropy FLL in YBCO (ab) plane
YBCO YBCO 124

4. Vortex pinning by twin boundaries in YBCO123

5. Flux Line Lattice destruction by columnar defects in BSCCO

6. Observation flux Line Lattice in the Organic Superconductors

7. Vortices in MgB2

8. The VL in LuNi2B2C for B=1840 Gs
Add data V3Si ?
The right insert is the Fourier transform, the left one autocorrelation pattern

9. Anisotropy in the long-range order
LuNi2B2C
V3Si
PRB (2000)
Anisotropy in the long-range order

10. RHOMBIC -TO–SQUARE VORTEX LATTICE TRANSITION
PRB (2000)
LuNi2B2C
V3Si

11. N. Saha, R.Surdeanu, M.Marchevsky et al PRB (2000)

12. Vortex Structure in ErNi2B2C
H=8 Oe, Td=5.5K

13. Vortex Structure in HoNi2B2C
H= 17 Oe, Td= 4.3K

14. Magnetoelastic tetragonal-to-orthorhombic distortion for RNi2B2C

15. Magnetic structure for RNi2B2C

16. Superconducting and antiferromagnetic transition for RNi2B2C

17. Magnetic Flux Structure in TbNi2B2C
The direct evidence for magnetic nature of the pinning by twin boundaries in RNi2B2C R=Er (at least partial)

18. SUMMARY
The Bitter decoration provides a distinctive high-resolution technique for observation of anisotropy FLL, vortex pinning as well as antiferromagnetic domain in magnetic superconductors.
We have observed magnetic (vortex) structure for wide range magnetic fields and temperatures for superconducting and normal states for family RNi2B2C single crystals . We find the crystalographic ordered vortex structures in HoNi2B2C and ErNi2B2C result from pinning by magnetic twin boundaries in antiferromagnetic state.
The domain magnetic structure have revealed in AF state in TbNi2B2C for the first time by Bitter decoration technique.
Taking to account the symmetry of magnetoelastic distortions at AF transition in RNi2B2C we can predict that for DyNi2B2C at temperatures less than TN should be observed structures similar observed here for HoNi2B2C