Kevin Storr
Prairie View A&M University, USA
Title: Condensed matter physics at the threshold of the extreme environments of temperature and magnetic fields
Biography
Biography: Kevin Storr
Abstract
In the area of Condensed Matter, we use extreme environmental conditions of temperature (down to 20 millikelvin) and magnetic field (≤ 45 Tesla) to elucidate and tune the electronic, magnetic and thermal properties of candidate materials using several techniques. Three of our most commonly employed techniques are: electrical transport, magnetic torque cantilever and specific heat. Here we present results from three classes of materials, each studied using similar methods: organic conductors, heavy fermion systems and hybridized graphene. λ-(BETS)2FeCl4 is a quasi, two dimensional, layered, anisotropic organic conductor which has shown three states below liquid helium temperature: an antiferromagnetic-insulator state, metallic state, and a field induced superconducting (FISC) ground states with observed re-entrance. Nd1−xCexCoIn5 is 115 heavy fermion single crystal which exhibits unconventional superconductivity due to being an intermetallic compounds with large electron effective masses. This material can progress from having local moment magnetism to a heavy fermion with the gradual substitution of Nd with Ce. This leads to an adjustment of the availability of 4f electron coupling. Hybridized graphene and hexagonal boron nitride (h-BNC) domains as a disordered 2D electronic system was studied using magnetoelectric transport measurements. It clearly showed show an insulating to a metallic anomalous transition during the cooling process which we modulated with electron and hole-doping. It was concluded that in comparison to other 2D systems, that in h-BNC the transition came about from percolation associated with the metallic graphene and hopping conduction along edge states.