Crystal Structure, Magnetism, and Electronic Properties of New Rare-Earth-Free Ferromagnetic MnPt5As

TL;DR

This paper reports the synthesis, structure, and magnetic properties of a new rare-earth-free ferromagnetic compound MnPt5As, demonstrating its potential as a high-performance magnetic material with a Curie temperature around 301 K.

Contribution

It introduces a novel ferromagnetic material MnPt5As, synthesized via high-temperature pellet methods, with detailed analysis of its structure, magnetism, and electronic properties, expanding the family of rare-earth-free magnets.

Findings

MnPt5As crystallizes in a tetragonal structure with space group P4/mmm.

MnPt5As exhibits ferromagnetism with a Curie temperature of approximately 301 K.

Electronic structure calculations show magnetism arises from hybridization of Mn and Pt d orbitals.

Abstract

The design and synthesis of targeted functional materials have been a long-term goal for material scientists. Although a universal design strategy is difficult to generate for all types of materials, however, it is still helpful for a typical family of materials to have such design rules. Herein, we incorporated several significant chemical and physical factors regarding magnetism, such as structure type, atom distance, spin-orbit coupling, and successfully synthesized a new rare-earth-free ferromagnet, MnPt5As, for the first time. MnPt5As can be prepared by using high-temperature pellet methods. According to X-ray diffraction results, MnPt5As crystallizes in a tetragonal unit cell with the space group P4/mmm (Pearson symbol tP7). Magnetic measurements on MnPt5As confirm ferromagnetism in this phase with a Curie temperature of ~301 K and a saturated moment of 3.5 uB per formula. Evaluation by applying the Stoner Criterion also indicates that MnPt5As is susceptible to ferromagnetism. Electronic structure calculations using the WIEN2k program with local spin density approximation imply that the spontaneous magnetization of this phase arises primarily from the hybridization of d orbitals on both Mn and Pt atoms. The theoretical assessments are consistent with the experimental results. Moreover, the spin-orbit coupling effects heavily influence on magnetic moments in MnPt5As. MnPt5As is the first high-performance magnetic material in this structure type. The discovery of MnPt5As offers a platform to study the interplay between magnetism and structure.