Aarhus Universitets segl

Department of Chemistry Seminar Series: Professor J. Paul Attfield, University of Edinburgh (Vært: Martin Bremholm)

New Materials from High Pressure

Oplysninger om arrangementet


Onsdag 26. oktober 2022,  kl. 15:00 - 17:00


1514-213, Aud I, Institut for Kemi

15.00-15.15: coffee & cake in foyer
15.15-16: scientific talk in Auditorium I (everyone is welcome)
16.15-17: Q&A session for PhD students in Auditorium I (2 reference papers will be uploaded in Brightspace)

High pressure methods are important for synthesising new materials, and exploring changes of structure and property in dense matter. High pressure materials science will be introduced briefly, and applications for materials chemistry will be illustrated with reference to new oxides and nitrides. High pressure often stabilises cations in unusual oxidation or coordination environments. Examples are perovskites with Mn2+ at A-sites, such as MnVO3 [1], the double perovskite Mn2FeReO6 [2] and double double perovskites MnRMnSbO6 and CaMnFeReO6 with order of A and B site cations [3,4,5]. A remarkable variety of new iron oxides has recently been reported at high pressures, and we have explored the substitutional chemistry of Fe4O5. Complex magnetic orders are observed in MnFe3O5 [6] and CoFe3O5 [7], while CaFe3O5 (prepared at ambient pressure) shows electronic phase separation driven by trimeron formation [8]. A new quantum phenomenon, quantised weak ferromagnetism, has recently been discovered in the perovskite YRuO3 based on the unusual Ru3+ state [9]. A high pressure method using sodium azide has recently been developed to synthesise nitrides in high oxidation states giving the iron(IV) nitride, Ca4FeN4 [10], an electron-localised Ni2+ nitride, Ca2NiN2 [11], and a rare example of a nitride perovskite, LaReN3 12]. The latter material can be decomposed to give novel reduction products LaReN2.5 and layered LaReN2 demonstrating topotactic reduction chemistry analogous to that of perovskite oxides like LaNiO3 and SrFeO3.

1. M. Markkula, A.M. Arevalo-Lopez, A. Kusmartseva, J.A. Rodgers, C. Ritter, H. Wu and J.P. Attfield. Phys. Rev. B 84, 094450 (2011).
2. Arévalo-López A.M., McNally G.M., Attfield J.P. Angew. Chem. 54, 12074 (2015).
3. E. Solana-Madruga, Á. M. Arévalo-López, A. J. Dos Santos-García, E. Urones-Garrote, D. Ávila-Brande, R. Sáez-Puche, J. P. Attfield. Angew. Chem. 55, 9340 (2016).
4. G. M. McNally, Á. M. Arévalo-López, P. Kearins, F. Orlandi, P. Manuel, J. P. Attfield. Chem. Mat. 29, 8870 (2017).
5. K. Ji, K. N. Alharbi, E. Solana-Madruga, G. T. Moyo, C. Ritter, J. P. Attfield, Angew. Chem. Int. Ed. 2021, 60, 22248.
6. K. H. Hong, G. M. McNally, M. Coduri, J. P. Attfield, Zeitschrift für Anorg. und Allg. Chemie 2016, 642, 1355–1358; K. H. Hong, A. M Arevalo-Lopez, M. Coduri, G. M. McNally, J. P. Attfield J. Mater. Chem. C 2018, 6, 3271–3275.
7. K. H. Hong, E. Solana-Madruga, M. Coduri, J. P. Attfield Inorg Chem. 2018, 57 (22), 14347-14352
8. K. H. Hong, A. M. Arevalo-Lopez, J. Cumby, C. Ritter, J. P. Attfield Nature Commun. 2018, 9, 2975.
9. K. Ji, A. Paul, E Solana-Madruga, A. M. Arevalo-Lopez, U. V. Waghmare, and J. P. Attfield Phys. Rev. Mat. 2020, 4, 091402(R).
10. S. D. Kloß, A. Haffner, P. Manuel, M. Goto, Y. Shimakawa, J. P. Attfield, Nat. Commun. 2021, 12, 571.
11. S. D. Kloß, J. P. Attfield, Chem. Commun. 2021, 57, 10427.
12. S. D. Kloß, M. L. Weidemann, J. P. Attfield, Angew. Chem. Int. Ed. 2021, 60, 22260.