Emergent 1/3 magnetization plateaus in pyroxene CoGeO3

Abstract

Despite the absence of an apparent triangular pattern in the crystal structure, we observe unusually well-pronounced 1/3 magnetization plateaus in the quasi-one-dimensional Ising spin chain compound CoGeO3 which belongs to the class of pyroxene minerals. We succeeded in uncovering the detailed microscopic spin structure of the 1/3 magnetization plateau phase by means of neutron diffraction. We observed changes of the initial antiferromagnetic zero-field spin structure that resemble a regular formation of antiferromagnetic “domain wall boundaries,” resulting in a kind of modulated magnetic structure with a 1/3-integer propagation vector. The net ferromagnetic moment emerges at these “domain walls” whereas two thirds of all antiferromagnetic chain alignments can be still preserved. We propose a microscopic model on the basis of an anisotropic frustrated square lattice to explain the observations.Received 2 April 2021Revised 28 June 2021Accepted 19 July 2021DOI:https://doi.org/10.1103/PhysRevResearch.3.L032037Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAntiferromagnetismDielectric propertiesDomain wallsFerrimagnetismFerromagnetismFrustrated magnetismMagnetic anisotropyMagnetic phase transitionsMagnetic susceptibilityMagnetization switchingSpintronicsTechniquesMagnetization measurementsNeutron scatteringSpin chainsCondensed Matter, Materials & Applied Physics