2019/07/31 by E. S. Zhukova, Zhukova, E. S., A. Melentyev +19 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties of Alloys #Metal and Thin Film Mechanics #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.1907.13374
openalex publication_date 2019/07/31 · openalex created_date 2022/07/28 · openalex updated_date 2026/07/28
Tm1-xYbxB12 dodecaborides represent model objects for the studies of quantum\ncritical behavior, metal-insulator transition and complex\ncharge-spin-orbital-phonon coupling phenomena. In spite of intensive\ninvestigations, the mechanism of the ground state formation in this strongly\ncorrelated electron system remains a subject of active debates. We have\nperformed first systematic measurements of temperature-dependent spectra of\ninfrared conductivity of Tm0.19Yb0.81B12 at frequencies 40-35000 cm-1 and in\nthe temperature interval from 300 K down to 10 K. Analysis of the temperature\nevolution of the observed absorption resonances is performed. Their origin is\nassociated with the Jahn-Teller instability in the cubic lattice which results\nin the rattling modes of the rare earth ions and leads to emergence of both the\nintra-gap mixed-type collective excitations and the dynamic charge stripes.\nTemperature dependent effective mass of charge carriers is determined and a\npicture is presented of the multiple relaxation channels and the transformation\nof the manybody states at different temperatures. We argue in favor of\nelectronic phase separation scenario which is valid both for the\nmetal-insulator transition and for the formation of the nanoscale filamentary\nstructure in Tm1-xYbxB12 compounds.\n