Bonding and Suppression of a Magnetic Phase Transition in EuMn2P2

Berry T, Varnava N, Ryan DH, Stewart VJ, Rasta R, Heinmaa I, Kumar N, Schnelle W, Bhandia R, Pasco CM, Armitage NP, Stern R, Felser C, Vanderbilt D, Mcqueen TM (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Journal of the American Chemical Society American Chemical Society

Book Volume: 145

Pages Range: 4527-4533

Journal Issue: 8

DOI: 10.1021/jacs.2c11324

Abstract

Electrons in solids often adopt complex patterns of chemical bonding driven by the competition between energy gains from covalency and delocalization, and energy costs of double occupation to satisfy Pauli exclusion, with multiple intermediate states in the transition between highly localized, and magnetic, and delocalized, and nonmagnetic limits. Herein, we report a chemical pressure-driven transition from a proper Mn magnetic ordering phase transition to a Mn magnetic phase crossover in EuMn2P2 the limiting end member of the EuMn2X2 (X = Sb, As, P) family of layered materials. This loss of a magnetic ordering occurs despite EuMn2P2 remaining an insulator at all temperatures, and with a phase transition to long-range Eu antiferromagnetic order at TN ≈ 17 K. The absence of a Mn magnetic phase transition contrasts with the formation of long-range Mn order at T ≈ 130 K in isoelectronic EuMn2Sb2 and EuMn2As2. Temperature-dependent specific heat and 31P NMR measurements provide evidence for the development of short-range Mn magnetic correlations from T ≈ 250-100 K, interpreted as a precursor to covalent bond formation. Density functional theory calculations demonstrate an unusual sensitivity of the band structure to the details of the imposed Mn and Eu magnetic order, with an antiferromagnetic Mn arrangement required to recapitulate an insulating state. Our results imply a picture in which long-range Mn magnetic order is suppressed by chemical pressure, but that antiferromagnetic correlations persist, narrowing bands and producing an insulating state.

Involved external institutions

Johns Hopkins University (JHU) US United States (USA) (US) The State University of New Jersey (Rutgers) US United States (USA) (US) McGill University CA Canada (CA) National Institute of Chemical Physics and Biophysics / Keemilise ja Bioloogilise Füüsika Instituut (KBFI) EE Estonia (EE) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE)

How to cite

APA:

Berry, T., Varnava, N., Ryan, D.H., Stewart, V.J., Rasta, R., Heinmaa, I.,... Mcqueen, T.M. (2023). Bonding and Suppression of a Magnetic Phase Transition in EuMn2P2. Journal of the American Chemical Society, 145(8), 4527-4533. https://dx.doi.org/10.1021/jacs.2c11324

MLA:

Berry, Tanya, et al. "Bonding and Suppression of a Magnetic Phase Transition in EuMn2P2." Journal of the American Chemical Society 145.8 (2023): 4527-4533.

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