Role of <i>p</i>– <i>f</i> Hybridization in the Metal–Nonmetal Transition of PrRu₄P₁₂

Abstract

Electronic state evolution in the metal-non-metal transition of PrRu4P12 has\nbeen studied by X-ray and polarized neutron diffraction experiments. It has\nbeen revealed that, in the low-temperature non-metallic phase, two inequivalent\ncrystal-field (CF) schemes of Pr3+ 4f^2 electrons with Gamma_1 and Gamma_4^(2)\nground states are located at Pr1 and Pr2 sites forming the bcc unit cell\nsurrounded by the smaller and larger cubic Ru-ion sublattices, respectively.\nThis modulated electronic state can be explained by the p-f hybridization\nmechanism taking two intermediate states of 4f^1 and 4f^3. The p-f\nhybridization effect plays an important role for the electronic energy gain in\nthe metal-non-metal transition originated from the Fermi surface nesting.\n