Appreciable magnetic moment and energy density in single step normal route synthesized MnBi

TL;DR

This study successfully synthesizes MnBi with notable magnetic properties using a simple method, demonstrating its potential as a rare-earth-free permanent magnet material.

Contribution

It presents a single-step synthesis route for high-purity MnBi with enhanced magnetic properties, suitable for permanent magnet applications.

Findings

Magnetic moment of 62 emu/g at 6 Tesla

Maximum energy product of 4.01 MGOe at 6 Tesla

Optimal heat treatment at 310°C for 48 hours

Abstract

We study the structural and magnetic properties of the MnBi inter-metallic compound. The LTP (Low Temperature Phase) MnBi compound is successfully synthesized in single step by vacuum encapsulation technique and rapid quenching from phase formation temperature. The phase purity and the magnetic moments of MnBi are highly dependent on heat treating schedule. The best phase purity and the magnetic moment are found for a sample heat treated at 310oC for 48h. Rietveld fitted X-ray diffraction (XRD) patterns revealed that the studied MnBi compound is crystallized in hexagonal P63/mmc space group with minute presence of unreacted Bi and Mn phases. The scanning electron microscopy (SEM) study is carried out to visualize the grains morphology and phase identification. The bulk MnBi powder showed appreciable magnetic moment of (62emu/g at 6Tesla) and maximum energy product (BHmax of 4.01MGOe at 6Tesla). The magnetic properties of synthesized MnBi show that it could be a potential candidate for rare earth free permanent magnets.