News & Events

 

Chemistry Weekly Seminar - Dr. Robert Green

Posted on 2018-12-17 in Events
Feb 8, 2019



Title:

Metal-insulator transitions and unconventional magnetic order in negative charge transfer oxides

Abstract:

In some correlated transition metal oxide compounds having high formal oxidation states, the observed cation orbital degrees of freedom are at odds with what is expected from the formal valence. As a consequence, holes are self-doped into ligand states and the materials are classified as negative charge transfer compounds, often having very different electronic structures and emergent properties than expected from the formal oxidation state picture. I will show that the trivalent perovskite nickel oxides are a clear example of such a material. Using a unique ligand field theory model in conjunction with synchrotron x-ray spectroscopy experiments, we have come to understand the origin of the novel electronic and magnetic phases of these nickelates [1,2], and have used this knowledge to tune new ground states useful for device applications [3,4].  Lastly, I will show that formally tetravalent iron oxides fall into this material class as well, and also exhibit very interesting electronic and magnetic phenomena [5].

References

1. Nat. Comm. 7, 13017 (2016)
2. Phys. Rev. B 94, 195127 (2016)
3. Nat. Phys. 14, 0197 (2018)
4. PNAS 115, 9515 (2018)
5. Phys. Rev. B(R) 98, 201115 (2018)

Back to News Listing

Related Articles

Chemistry Weekly Seminar - Dr. Alex Boika

Posted on 2019-09-04

Professor Alex Boika, University of Akron, Dept. of Chemistry, will present a seminar in THORV 124 at 1:30PM


Chemistry Weekly Seminar - Dr. Stephen Foley

Posted on 2019-09-04

Professor Stephen Foley, Department of Chemistry, will present a seminar in THORV 124 at 1:30PM


Chemistry Weekly Seminar - PhD Candidate Tyler Morhart

Posted on 2019-09-04

Tyler Morhart, PhD Candidate, Dept. of Chemistry, will present a seminar in THROV 124 at 1:30PM


Chemistry Weekly Seminar - PhD Candidate David Sowah-Kuma

Posted on 2019-09-04

David Sowah-Kuma, PhD Candidate, Department of Chemistry, will present a seminar in THORV 124 at 1:30PM


Chemistry Weekly Seminar - Dr. Scott Rosendahl

Posted on 2019-09-04

Scott Rosendahl from the Canadian Light Source will present a seminar in THORV 124 at 1:30PM


Chemistry Weekly Seminar - Dr. Jennifer Love

Posted on 2019-09-04

Professor Jennifer Love, University of British Columbia, Dept. of Chemistry, will present a seminar in THORV 124 at 1:30PM