Xu, Bîng Marsik, Premysl Sheveleva, Evgeniia Lyzwa, Fryderyk Louat, A. Brouet, V. Munzar, Dominik Bernhard, Christian 2020-01-15 With optical spectroscopy we provide evidence that the insulator-metal transition in Sr2Ir1−xRhxO4 occurs close to a crossover from the Mott- to the Slater-type. The Mott gap at x=0 persists to high temperature and evolves without an anomaly across the Néel temperature, TN. Upon Rh doping, it collapses rather rapidly and vanishes around x=0.055. Notably, just as the Mott gap vanishes yet another gap appears that is of the Slater-type and develops right below TN. This Slater gap is only partial and is accompanied by a reduced scattering rate of the remaining free carriers, similar as in the parent compounds of the iron arsenide superconductors. application/pdf https://folia.unifr.ch/global/documents/308350 https://folia.unifr.ch/documents/308350/files/ber_osc.pdf https://folia.unifr.ch/documents/308350/files/ber_osc_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevLett.124.027402 info:eu-repo/semantics/openAccess License undefined Physical Review Letters. - 2020, vol. 124, no. 2, p. 027402 info:eu-repo/classification/udc/53 Optical signature of a crossover from Mott- to Slater-type gap in ${\mathrm{Sr}}_{2}{\mathrm{Ir}}_{1\ensuremath{-}x}{\mathrm{Rh}}_{x}{\mathrm{O}}_{4}$ http://purl.org/coar/resource_type/c_6501