Contact-less high-resolution magnetic measurement of electron transport

Electronic transport studies are important tool to get information on the electronic system and quality of a material. Recent progress in experimental techniques leads to higher resolution data, providing insight in physical processes on much finer scale. Many intriguing, particularly quantum phenomena of electron transport in solids emerge when conduction electrons are 'cold', with field induced kinetic energy ε < < κBT. We focus on phase transitions accompanied by abrupt changes of electrical conductivity in a narrow temperature range. Examples are superconducting-normal, metal-insulator, martensitic or the Verwey-transition in Fe3O4. In many cases a shape and details in the transition are blurred with increasing current density. But the 'cold' conduction electrons may reveal details and offer high-resolution data for detailed analysis of elastic and inelastic electron scattering.