Pressure-induced valence transitions: squeezing electrons from big orbitals to smaller ones

Simple item page
dc.contributor.authorLing, CDen_AU
dc.contributor.authorKennedy, BJen_AU
dc.contributor.authorAvdeev, Men_AU
dc.date.accessioned2021-08-02T04:57:54Zen_AU
dc.date.available2021-08-02T04:57:54Zen_AU
dc.date.issued2017-01-31en_AU
dc.date.statistics2021-07-15en_AU
dc.description.abstractWhile bonds in solid-state compounds always have some degree of covalent character, the ionic approximation is usually sufficient to understand their “crystal chemistry” using concepts like the effective ionic radius (IR). IR predicts that an atom will shrink as its oxidation state increases. This occurs gradually as electrons are removed within a shell (e.g., IR(Ir3+) = 0.68, IR(Ir4+) = 0.625, IR(Ir5+) = 0.57 Å in 6-fold coordination), but removing the last electron of a shell produces a much more pronounced change (e.g., IR(Bi3+) = 1.03, IR(Bi5+) = 0.76 Å). For a compound with a suitable combination of cations, it should therefore be possible to effect a net reduction in volume by transferring an electron from one to the other. Temperature and/or pressure could drive such a valence state transition; but in practice, this is extremely rare, with only three cases reported until recently. We tested this idea systematically in a series of high-pressure X-ray and neutron diffraction andspectroscopy experiments on six candidate materials containing Bi3+ with 4d or 5d metal cations. We observed a valence state transition in every case, suggesting that they are far more common than previously thought. This talk will present both published and unpublished experimental results, as well as ab initio calculations that shed light on the finely balanced electronic states of these compounds. The potential for tuning these transitions closer to ambient pressures, and of inverting the effect to give a volume change with an electronic stimulus, will be discussed. © 2021en_AU
dc.identifier.citationLing, C. D., Kennedy, B. J., & Avdeev, M. (2017). Pressure-induced valence transitions: squeezing electrons from big orbitals to smaller ones. Paper presented at the Australian and New Zealand Institutes of Physics Annual Condensed Matter and Materials Meeting, 31 January - 3 February, 2017, Charles Sturt University, Wagga Wagga, NSW, Australia. (pp.106). Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2017/Wagga_2017_Conference_Handbook.pdfen_AU
dc.identifier.conferenceenddate3 February 2017en_AU
dc.identifier.conferencenameAustralian and New Zealand Institutes of Physics Annual Condensed Matter and Materials Meetingen_AU
dc.identifier.conferenceplaceWagga Wagga, NSWen_AU
dc.identifier.conferencestartdate31 January 2017en_AU
dc.identifier.otherFN3en_AU
dc.identifier.pagination106en_AU
dc.identifier.urihttps://physics.org.au/wp-content/uploads/cmm/2017/Wagga_2017_Conference_Handbook.pdfen_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/11223en_AU
dc.language.isoenen_AU
dc.publisherAustralian Institute of Physicsen_AU
dc.subjectNeutron diffractionen_AU
dc.subjectX-ray diffractionen_AU
dc.subjectPressure dependenceen_AU
dc.subjectValenceen_AU
dc.subjectOxidationen_AU
dc.subjectExpansionen_AU
dc.subjectCrystal-phase transformationsen_AU
dc.subjectAtomic ionsen_AU
dc.titlePressure-induced valence transitions: squeezing electrons from big orbitals to smaller onesen_AU
dc.typeConference Abstracten_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Wagga_2017_Conference_Handbook.pdf
Size:
11.03 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications