STM/STS studies on vortex and electronic state in YBa2Cu3Oy

✍ Scribed by Terukazu Nishizaki; Kenji Shibata; Makoto Maki; Norio Kobayashi

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 542 KB
• Volume: 437-438
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2006.03.012

✦ Synopsis

Low temperature scanning tunneling microscopy (LT-STM) studies have been performed on the LT-cleaved and the chemically etched surface of YBa 2 Cu 3 O y single crystals. We find that the vortex structure can be observed on the chemically etched surface of YBa 2 Cu 3 O y as a function of temperature and magnetic field. At low magnetic fields, we observed a slightly distorted triangular lattice, which is attributed to the Bragg-glass phase. The triangular lattice transforms into a disordered structure in high magnetic fields above the order-disorder transition H * (T). We observed that the disordered vortices form small clusters comprising 5-and 7-fold coordination pairs. These microscopically determined vortex structures are in good agreement with the vortex matter phase diagram derived from the macroscopic measurements, thus providing the evidence of the field-driven transition in the vortex solid phase of YBa 2 Cu 3 O y .