Mn(Pt1−xPdx)5P: Isovalent Tuning of Mn Sublattice Magnetic Order

Abstract

We report the growth and characterization of MnPd5P, a rare-earth-free ferromagnet, with TC approximate to 295 K and planar anisotropy, and conduct a substitutional study with its antiferromagnetic analog MnPt5P. All compounds in the family adopt the layered anti-CeCoIn5-type structure with the space group P4/mmm, and EDS and x-ray diffraction results indicate that MnPt5P and MnPd5P form a complete solid solution. Based on measurements of the temperature-and field-dependent magnetization and resistance, we construct a temperature -composition (T -x) phase diagram for Mn(Pt1-xPdx )5P and demonstrate that the essentially antiferromagnetic order found in MnPt5P is extraordinarily sensitive to Pd substitution. At low Pd fractions (x 0.010, Mn(Pt1-xPdx )5P undergoes a only single transition into the ferromagnetic phase. The Curie temperature initially increases rapidly with x, rising from TC approximate to 197 K at x = 0.013 to a maximum of TC approximate to 312 K for x approximate to 0.62, and then falling back to TC approximate to 295 K for pure MnPd5P (x = 1.00). Given that Pt and Pd are isoelectronic, this work raises questions as to the origin of the extreme sensitivity of the magnetic ground state and the nature of the re-entrant ferromagnetism at dilute Pd levels.This article is published as Slade, Tyler J., Ranuri S. Dissanayaka Mudiyanselage, Nao Furukawa, Tanner R. Smith, Juan Schmidt, Lin-Lin Wang, Chang-Jong Kang et al. "Mn (Pt 1− x Pd x) 5 P: Isovalent tuning of Mn-sublattice magnetic order." Physical Review B 107, no. 13 (2023): 134429. DOI: 10.1103/PhysRevB.107.134429. Copyright 2023 American Physical Society. Posted with permission. DOE Contract Number(s): AC02-07CH11358; FOA-0001276; NSF-DMR-2053287; DMR-1644779; 2022R1C1C1008200