Direct Observation of Melting of the Vortex Solid in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Bi</mi><mrow><msub><mrow><mi></mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mi>Sr</mi><mrow><msub><mrow><mi></mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mi>CaCu</mi><mrow><msub><mrow><mi></mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mi>O</mi><mrow><msub><mrow><mi></mi></mrow><mrow><mn>8</mn><mo>+</mo><mi>δ</mi></mrow></msub></mrow></math></span> Single Crystals

A. Oral; J. C. Barnard; S. J. Bending; I. I. Kaya; S. Ooi; T. Tamegai; M. Henini

doi:10.1103/PhysRevLett.80.3610

Direct Observation of Melting of the Vortex Solid in $Bi_{2} Sr_{2} CaCu_{2} O_{8 + δ}$ Single Crystals

A. Oral, J. C. Barnard, S. J. Bending, I. I. Kaya, S. Ooi, T. Tamegai, and M. Henini

Phys. Rev. Lett. 80, 3610 – Published 20 April 1998

Abstract

A scanning Hall probe microscope has been used to directly observe the vortex lattice melting transition in $Bi_{2} Sr_{2} CaCu_{2} O_{8 + δ}$ single crystals. Below the melting line, the system settles into a fairly well-ordered vortex solid which undergoes pronounced rotations as the field is increased due to incommensurability effects. Vortex contrast is lost abruptly and discontinuously at the melting line consistent with a first order transition. Vortex profiles appear to be strongly broadened by two-dimensional fluctuations which grow much stronger as the melting line is approached from below, suggesting that melting and decoupling are almost simultaneous.