Structural and magnetic properties of new members of the 3:29 phase from the Ce-Fe-Mn system and 1:11 from the Ce-Co-Mn

The Ce-Fe-Mn and Ce-Co-Mn systems have been re-visited with the intent of finding new potential phases for application as permanent magnets. Two new ternary compounds, Ce-3(Fe0.638Mn0.362)(29) (Nd-3(Fe,Ti)(29)-type, space group P2(1)/c, No.14, Pearson Symbol mP128) and CeCo8Mn3 (Ce(Ni,Mn)(11)-type, space group P4/mbm, No. 127, Pearson Symbol tP24) have been discovered in the compositional range where the Ce-2(T,Mn)(17) (T = Fe, Co) phases are expected to exist with a (H)-Th2Ni17-type structure (space group P6(3)/mmc, No. 194, Pearson Symbol hP38). Detailed investigations of the crystal structures have been performed using X-ray powder diffraction (XRPD) with supporting energy-dispersive X-ray (EDS) analysis. Compositions of the new compounds have been defined based on the EDS analysis as follows: Ce9.2Fe92.9Mn32.9 and Ce9.2Co65.2Mn25.6. A short discussion on the crystal structure peculiarities of the 1:5, 1:11, 1:12, 2:17 and 3:29 compounds in the Ce-T-Mn (T = Fe, Co, Ni, Cu) systems has been made. We present magnetic measurements on selected representatives of the studied phases. The most interesting being the Ce-3(Fe0.63Mn0.362)(29) phase which has a transition temperature well above room temperature. CeNi4.95Mn6.05 and CeCo8Mn3 exhibits properties characteristic of a canted antiferromagnetic state. (C) 2020 The Authors. Published by Elsevier B.V.

Automated summary

The Ce-Fe-Mn and Ce-Co-Mn systems have been re-investigated, leading to the discovery of two new potential phases for permanent magnets: Ce-3(Fe0.638Mn0.362)(29) and CeCo8Mn3. These compounds exhibit unique crystal structures and magnetic properties.