Magnetic phase diagram of the solid solution LaMn2(Ge1-xSix)2 (0 ≤ x ≤ 1) unraveled by powder neutron diffraction

Stefanie Siebeneichler; Alexander Ovchinnikov; Brianna Bosch-Santos; Gabriel A Cabrera-Pasca; Roxana Flacau; Qingzhen Huang; Artur W Carbonari; Dominic Ryan; Anja-Verena Mudring

doi:10.1038/s41598-022-12549-y

Magnetic phase diagram of the solid solution LaMn₂(Ge_1-xSi_x)₂ (0 ≤ x ≤ 1) unraveled by powder neutron diffraction

Sci Rep. 2022 Jun 3;12(1):9248. doi: 10.1038/s41598-022-12549-y.

Authors

Affiliations

¹ Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16 C, 10691, Stockholm, Sweden.
² Material Measurement Laboratory, National Institute of Standards and Technology-NIST, Gaithersburg, MD, 20899, USA.
³ Instituto de Pesquisas Energéticas e Nucleares-IPEN-CNEN/SP, São Paulo, SP, 05508-000, Brazil.
⁴ Programa de Pós-Graduação em Ciência e Engenharia de Materiais-PPGCEM, Universidade Federal do Pará, Ananindeua, PA, 67130 660, Brazil.
⁵ Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, ON, K0J 1J0, Canada.
⁶ Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
⁷ The Centre for the Physics of Materials and the Physics Department, McGill University, 3600 University St., Montreal, QC, H3A 2T8, Canada.
⁸ Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16 C, 10691, Stockholm, Sweden. anja-verena.mudring@mmk.su.se.
⁹ Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark. anja-verena.mudring@mmk.su.se.

Abstract

The structural and magnetic properties of the ThCr₂Si₂-type solid solution LaMn₂(Ge_1-xSi_x)₂ (x = 0.0 to 1.0) have been investigated employing a combination of X-ray diffraction, magnetization and neutron diffraction measurements, which allowed establishing a magnetic composition-temperature phase diagram. Substitution of Ge by Si leads to a compression of the unit cell, which affects the magnetic exchange interactions. In particular, the magnetic structure of LaMn₂(Ge_1-xSi_x)₂ is strongly affected by the unit cell parameter c, which is related to the distance between adjacent Mn layers. Commensurate antiferromagnetic layers and a canted ferromagnetic structure dominate the Si-rich part of the solid solution, whilst an incommensurate antiferromagnetic flat spiral and a conical magnetic structure are observed in the Si-poor part.

Abstract

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