Thermal avalanches near a Mott transition

Lashley, J. C. and Gofryk, K. and Mihaila, B. and Smith, J. L. and Salje, E. K. H. (2014) Thermal avalanches near a Mott transition. Journal of Physics: Condensed Matter, 26 (3). 035701. ISSN 0953-8984 DOI https://doi.org/10.1088/0953-8984/26/3/035701

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Abstract

We probe the volume collapse transition (ΔV/Vo ~ 15%) between the isostructural γ and α phases (T ~ 100 K) of Ce0.9Th0.1 using the Hall effect, three-terminal capacitive dilatometry, and electrical resistivity measurements. Hall effect measurements confirm the itinerant ground state as the carrier concentration increases by a factor of 7 in the α phase, γ phase (nH = 5.28 × 1026 m−3), and the α phase (nH = 3.76 × 1027 m−3). We were able to detect a noise spectrum consisting of avalanches while slowly varying the temperature through the hysteretic region. We surmise that the avalanches originate from intergranular stresses at the interfaces between partially transformed high-volume and low-volume phases. The statistical distribution of avalanches obey power laws with energy exponent epsilon sime 1.5. Hall effect measurements, combined with universal critical exponents, point to short electron mean-free percolation pathways and carrier localization at phase interfaces. Carrier localization was predicted many years ago for elemental cerium by Johansson (1974 Phil. Mag. 30 469).

Item Type:	Article
Uncontrolled Keywords:	2013AREP; IA67;
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	Journal of Physics: Condensed Matter
Volume:	26
Page Range:	035701
Identification Number:	https://doi.org/10.1088/0953-8984/26/3/035701
Depositing User:	Sarah Humbert
Date Deposited:	05 May 2014 15:12
Last Modified:	09 May 2014 14:42
URI:	http://eprints.esc.cam.ac.uk/id/eprint/3044

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