Use of the bright field shadow technique to study superconductivity in the electron microscope

Abstract

Our thanks are due to Professor Sir Nevill Mott, F.R.S., and Dr. W. H. Taylor, of the Cavendish Laboratory, and Professor G. Puppi, of the Institute of Physics of Bologna, for their encouragement. We are grateful to Dr. P. B. Hirsch, F.R.S., and Dr. M. J. Whelan for helpful discussions and suggestions. We also wish to thank Mr. F. Saddler, of the Royal Society Mond Laboratory, for advice on techniques and for provision of liquid helium. One of us (M. J. G.) is indebted to the Department of Scientific and Industrial Research for a maintenance grant, and to Queens' College, Cambridge, for the award of a Research Studentship. The bright field shadow technique has been used to study the disturbance in the magnetic field of the objective lens of an electron microscope produced by a superconductor cooled in a liquid helium stage.