Fundamentals of charged devices: Energy changes in a capacitor medium

¹ Device Materials Group, Materials and Metallurgy Department, University of Cambridge Pembroke Street, Cambridge, CB2 3QZ, UK, EU
² Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR CNRS 8520, Département Hyperfréquences et Semi-conducteurs, Université des Sciences et Technologies de Lille Avenue Poincaré, BP 69, 59652 Villeneuve d'Ascq Cedex, France, EU

Received: 24 February 2013
Accepted: 25 February 2013

Abstract

Capacitors and derivative devices continue to be as relevant as ever, both at the frontiers of scientific and technological research and in the development of commercial products. Central to such pursuits is the essential requirement that all aspects of the work done in charging or discharging capacitors are clearly understood. Surprisingly, there is a very significant disagreement among standard texts and journal publications regarding this topic. The present work elaborates a thorough analysis of energy changes in a capacitor medium in terms of thermodynamic work and its extension to the more general, electrostatic energy change. Our conclusions agree, for example, with those of Volker Heine, but not with texts by Pippard or Callen. We also note that electric and magnetic analogues are not equivalent.