English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

An unusual published energy versus wave vector curve extending to the zoneedge determined by ARPES in 5% La-doped SrTiO3 is interpreted usingmixed-polaron theory. After modification of the theory to permit tight-bindingbare energy bands and anisotropy, a fit is made to the 24 points nearest to theFermi energy, adding constraints (a) that the Fermi volume is approximatelyequal to that determined from the carrier concentration, and (b) that thetransport mass from experiments is approximately twice the bare mass. In orderto fit the remaining five of 29 observed points we empirically add the effectof a kink. The fit to all points is good. From the parameters of the fit to the24 points it appears that: (a) The energy overlap integral for the narrow bandin the heavy direction has the opposite sign to that for the wide band,implying that it is energetically favourable for the nearly small polarons tobe centred in between two sites; and (b) The narrower energy band in the theorymay be nearly-small-polaron like in the heavy direction but large-polaron likein the other two directions. A simpler energy versus wave vector curve for a 1%La-doped crystal is discussed more briefly.

Energy versus wave vector for the conduction band of La-doped SrTiO_3 interpreted by mixed-polaron theory