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/

Global: Zendy Plus annual

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

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Temperature dependent electrical resistivity, crystal structure and heatcapacity measurements reveal a resistivity drop and metal to semiconductortransition corresponding to first order structural phase transition near 400 Kin Ca3Co4O9. The lattice parameter c varies smoothly with increasingtemperature, while anomalies in the a, b1 and b2 lattice parameters occur at ~400 K. Both Ca2CoO3 and CoO2 layers become distorted above ~ 400 K associatedwith the metal to semiconductor transport behavior change. Resistivity and heatcapacity measurements as a function of temperature under magnetic fieldindicates low spin contribution to this transition. Reduced resistivityassociated with this first order phase transition from metallic tosemiconducting behavior enhances the thermoelectric properties at hightemperatures and points to the metal to semiconductor transition as a mechanismfor improved ZT in high temperature thermoelectric oxides.

A Structural Phase Transition in Ca3Co4O9 Associated with Enhanced High Temperature Thermoelectric Properties