Report on a joint BIPM-EUROMET project for the fabrication of QHE samples by the LEP

The quantum Hall effect (QHE) samples fabricated by LEP according to specifications intended to optimize their usefulness in metrology are described. Their measured characteristics, notably carrier density, carrier mobility at zero magnetic field, dependence of the quantized resistance on temperature, measuring current, and the quality of electrical contacts, are reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>