Electronically driven lattice instability in the candidate Weyl semimetal Eu2Ir2O7

Date

Nov 27, 2018

Time

1:00 PM - 2:00 PM

Speaker

Prachi Telang

Affiliation

Crystal Growth and Characterisation Lab, Indian Institute of Science Education and Research Pune, I

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Christine Malbrich

Description

In the last few years, pyrochlore iridates A2Ir2O7 have garnered significant interest due to the prediction of novel topological phases in these materials. We investigated the electronic ground state of a solid solution between Weyl semimetal candidate Eu2Ir2O7 and an unusual metal Bi2Ir2O7. As the bigger Bi ion is gradually substituted for the smaller Eu ion, an anomalous observation was made - we found the unit cell volume, rather than increasing, undergo a rather large contraction with increasing Bi concentration. This is observed up to 3,5 % doping concentration (anomalous region) and for higher concentrations (>5%), the normal lattice expansion is recovered. This unusual observation was confirmed beyond ambiguity using very high-resolution synchrotron x-ray diffraction. We then show that the doping range over which the volume collapses, the electronic properties - specific heat, thermopower, resistivity, and magnetization - also exhibit corresponding changes suggestive of an electronic origin of the observed collapse. Evolution of properties in the anomalous region suggests proximity to Weyl semimetallic phase in Eu2Ir2O7.

Links

• Seminars at the IFW

Last modified: Nov 27, 2018, 1:08:39 AM