Investigation of the role of morphology on the magnetic properties of Ca2Mn3O8 materials

DOI: 10.1039/C7DT03053C

Authors: Laura J. Vera Stimpson (University of Kent) , Silvia Ramos (University of Kent) , Gavin B. G. Stenning (ISIS Neutron and Muon Source) , Marek Jura (ISIS Neutron and Muon Source) , Stephen Parry (Diamond Light Source) , Giannantonio Cibin (Diamond Light Source) , Donna Arnold (University of Kent)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Dalton Transactions

State: Published (Approved)
Published: September 2017
Diamond Proposal Number(s): 12777

Abstract: Ca2Mn3O8 exhibits a complex layered structure comprised of Mn3O84− layers separated by Ca2+ ions. In contrast with the more traditional triangular delafossite layered materials the Mn3O84− layers additionally exhibit an ordered vacancy, which forms a ‘bow-tie’ like arrangement of the Mn4+ ions. We report a comprehensive study of the magnetic properties of a series of Ca2Mn3O8 materials with different morphologies. EXAFS and XANES analysis confirm no differences in either manganese environment or oxidation state between materials. Apparent differences in magnetic order from SQUID magnetometry can be rationalised by uncompensated surface spins arising as a result of changes to the surface to volume ratio between morphologies. Furthermore, these data suggest these materials are potentially frustrated in nature, due to the triangular connectivity of Mn4+ spins, with a simple ‘spin-up/spin-down’ (↑↓) antiferromagnetic model unable to explain the data collected.

Diamond Keywords: Antiferromagnetism

Subject Areas: Chemistry, Materials, Physics


Instruments: B18-Core EXAFS

Added On: 02/10/2017 09:36

Discipline Tags:

Quantum Materials Physics Physical Chemistry Chemistry Magnetism Materials Science Inorganic Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)