Event 

Title:
Seminars at the Accelerator - Superconducting behaviour of interfaces in Graphite
When:
28.02.2012 - 28.02.2012
Where:
CMAM - Madrid
Category:
Informal seminars at the Accelerator

Description

Speaker: Pablo Esquinazi, University of Leipzig (Germany)

Superconducting Behaviour of Interfaces in Graphite: a way to room temperature?

Abstract:

In the last 11 years several reports speculated on the existence of high-temperature granular superconductivity in pure as well as doped, not intercalated, graphite. These speculations are based on the experimental observation of, for example, strong anisotropic superconducting-like magnetization loops in oriented graphite, low-field anomalous hysteresis in the magnetoresistance of micrometer small samples, magnetic-field driven metal-insulator-like transition, quantum oscillations in the magnetoresistance and field driven step-like changes in the resistance measured near internal interfaces. Taking into account the internal microstructure of the usually measured samples, it appears plausible that superconducting domains are located at internal interfaces between crystalline regions inside oriented graphite samples. In my talk I will shortly review the reported hints, discuss recently published studies on the influence of interfaces in the resistivity of graphite as well as evidence for superconductivity at interfaces found in other semiconductors. I will present new transport studies done on specially prepared graphite lamellae, which provide evidence for the existence of Josephson-coupled superconducting regions located at internal interfaces, and magnetization studies on specially treated graphite powders with apparent critical temperatures above 150K.

Venue

CMAM
Venue:
CMAM   -   Website
Street:
Faraday 3, Campus de Cantoblanco
ZIP:
28049
City:
Madrid
Country:
Country: es

Description

The seminar takes place at the meeting room of the CMAM