A. N. Azarevich, O. N. Khrykina, N. B. Bolotina, V. G. Gridchina, A. V. Bogach, S. V. Demishev, V. N. Krasnorussky, S. Yu. Gavrilkin, A. Yu. Tsvetkov, N. Yu. Shitsevalova, V. V. Voronov, K. I. Kugel, A. L. Rakhmanov, S. Gabani, K. Flachbart, N. E. Sluchanko
{"title":"Evidence for spin droplets (ferrons) formation in the heavy fermion metal CeB$_6$ with dynamic charge stripes","authors":"A. N. Azarevich, O. N. Khrykina, N. B. Bolotina, V. G. Gridchina, A. V. Bogach, S. V. Demishev, V. N. Krasnorussky, S. Yu. Gavrilkin, A. Yu. Tsvetkov, N. Yu. Shitsevalova, V. V. Voronov, K. I. Kugel, A. L. Rakhmanov, S. Gabani, K. Flachbart, N. E. Sluchanko","doi":"arxiv-2409.04139","DOIUrl":null,"url":null,"abstract":"The presented studies of resistivity (R), thermal conductivity (k) and\nspecific heat (C) at low temperature 1.8-7 K in magnetic field up to 90 kOe\nmade it possible to detect for the first time the exponential field dependences\nR(H), 1/k(H), $C(H) \\sim \\exp(-{\\mu}_{\\rm eff}H/kBT)$ of the charge transport\nand thermal characteristics in the so-called antiferroquadrupole (AFQ) phase of\nthe archetypal heavy-fermion CeB$_6$ hexaboride. From magnetoresistance\nmeasurements it is shown that in the AFQ state the effective magnetic moment\nvaries in the range ${\\mu}_{\\rm eff}(T) = 1.4$-1.9$\\mu$B, and its value is very\nclose to ${\\mu}_{\\rm eff}(\\tau)(T) = 2{\\mu}$B, derived from the field\ndependence of the relaxation time $|tau(H)$ observed in the heat capacity and\nthermal conductivity experiments. The phenomenological model proposed here\nallowed us to attribute the magnetic moments to spin droplets (ferrons), that\nappear in the bulk AFQ phase of CeB$_6$ crystals. The relevant electron phase\nseparation at the nanoscale, manifested by dynamic charge stripes, that leads\nto the formation of ferrons, was revealed from the analysis of low-temperature\nX-ray diffraction experiments using the maximum entropy method. We argue that\nthe Jahn-Teller collective mode of B$_6$ clusters is responsible for the charge\nstripe formation, which subsequently induces transverse quasi-local vibrations\nof Ce ions in the form of pairs and triples. These lead to 4f-5d spin\nfluctuations providing spin-polarons (ferrons) in the CeB$_6$ matrix.","PeriodicalId":501171,"journal":{"name":"arXiv - PHYS - Strongly Correlated Electrons","volume":"115 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Strongly Correlated Electrons","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.04139","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The presented studies of resistivity (R), thermal conductivity (k) and
specific heat (C) at low temperature 1.8-7 K in magnetic field up to 90 kOe
made it possible to detect for the first time the exponential field dependences
R(H), 1/k(H), $C(H) \sim \exp(-{\mu}_{\rm eff}H/kBT)$ of the charge transport
and thermal characteristics in the so-called antiferroquadrupole (AFQ) phase of
the archetypal heavy-fermion CeB$_6$ hexaboride. From magnetoresistance
measurements it is shown that in the AFQ state the effective magnetic moment
varies in the range ${\mu}_{\rm eff}(T) = 1.4$-1.9$\mu$B, and its value is very
close to ${\mu}_{\rm eff}(\tau)(T) = 2{\mu}$B, derived from the field
dependence of the relaxation time $|tau(H)$ observed in the heat capacity and
thermal conductivity experiments. The phenomenological model proposed here
allowed us to attribute the magnetic moments to spin droplets (ferrons), that
appear in the bulk AFQ phase of CeB$_6$ crystals. The relevant electron phase
separation at the nanoscale, manifested by dynamic charge stripes, that leads
to the formation of ferrons, was revealed from the analysis of low-temperature
X-ray diffraction experiments using the maximum entropy method. We argue that
the Jahn-Teller collective mode of B$_6$ clusters is responsible for the charge
stripe formation, which subsequently induces transverse quasi-local vibrations
of Ce ions in the form of pairs and triples. These lead to 4f-5d spin
fluctuations providing spin-polarons (ferrons) in the CeB$_6$ matrix.